JPS5975735A - Information transmission system - Google Patents

Abstract

PURPOSE:To obtain smoothly the right of transmission by a request acceptance command from a station which holds the right of transmission currently, by outputting a transmission right request command from a station which has a request to send. CONSTITUTION:In a network, a station A has a reader R and a printer P and a station B has only a printer P. A station C, on the other hand, has only a reader R. Each station is provided with a communication module. A communication module A' has a function for supply a command to other stations according to a request to send from a user and a communication module B' has only a function for operation command in response to input command information (command information). Then, a response command from a prefetch priority type soft master is waited for and once information on the transfer of the right of transmission is received, the right of transmission is obtained firstly to serve as a new soft master. The soft master station outputs a command equipped with a confirming function for connection states of stations constituting the communication system and a reporting function for the confirmed connection states to a communication circuit at specific intervals of time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information transmission system, for example, for transmitting and recording read image information to a recording unit provided at a remote location.

Conventionally, when transmitting information between multiple stations, it has been difficult to fairly grant each station the right to use a transmission path.

It is still difficult to know the contents of a plurality of stations connected to a transmission line, and for example, an error may occur if there are stations with the same station address.

Furthermore, information transmission in progress may be adversely affected by a station that joins the transmission system midway through.

The present invention has been made in view of the above points, and an object of the present invention is to facilitate the acquisition of transmission rights.

Another purpose is to perform appropriate processing in the event of an error in the transmission path.

Another purpose is to eliminate the negative effects of station participation and initialization.

Further, the present invention provides a transmission system suitable for information transmission using a loop-shaped transmission path.

The present invention will be explained below based on the drawings, but it goes without saying that the present invention can be applied to information transmission between multiple stations equipped with electronic devices such as word processors, office computers, and image processing devices. In the embodiment, an image reading device and an image recording device will be described as representative electronic devices.

FIG. 1 is a diagram showing the configuration of an image transmission network to which the present invention is applied. Reference numeral F denotes an optical transmission line υ consisting of an optical fiber cable. Stations A, B, and C are connected in a loop by this optical transmission line F, making it possible to exchange image information between the stations. Station A is equipped with a reader R that photoelectrically converts the original image and outputs a reading image signal, and a printer P that records an image on a recording material such as paper based on the long-term image signal. It is connected. On the other hand, at station B, only the aforementioned printer P is disposed, and at station C, only the aforementioned reader R is disposed.

Furthermore, stations A, B, and C are each provided with a communication module, which enables optical communication using optical transmission line F from station K.

FIG. 2 shows a structural sectional view of the reader R. 27 is a power switch. The original is placed face down on the original glass 3,
Its placement reference is on the back left side when viewed from the front. The original is pressed onto the original glass by the original cover 4.

The document is illuminated by a fluorescent lamp 2, and an optical path is formed such that the reflected light passes through mirrors 5, 7 and a lens 6 and is focused onto the surface of the CCD j. And this mirror 7
and mirror 5 move in the direction of the arrow at a relative speed of 2:1. That is, the optical unit moves from left to right at a constant speed while applying PLL by a DC servo motor. This moving speed is 180 on the outward path when irradiating the original.
At Ho/B eQ, the return route is 468 mrn/sea. The resolution in the sub-scanning direction is 161 ine s
It is Az. The size of originals that can be processed is A5 to A3, and the orientation of the originals is that A5, B5, and A4 are placed vertically, and B4° and A3 are placed horizontally. There are three return positions for the optical unit depending on the document size.

The first point is A5. The document reference position is common for BS and A4 J) 220mm, the second point is 564mm for B4, and the third point is the same for A3 (4!
This is where the iL is 8mm.

Next, regarding the main scanning direction, during main scanning, the maximum width of A4 paper can be 297 mm depending on the direction in which the document is placed. In order to resolve this at 16 pel/-, CO
Since D requires 4752 (=297x16) bits, this device uses two 2628-bit CCD array sensors and drives them in parallel. Therefore, under the conditions of 161 ineF1/min and 180 i$sec, the main scanning period=347.2μ8θC. C.O.
The transfer speed of D is f=FIG. 3 is a diagram of the operating section provided on the top surface of the reader. This operation section is used when image information read by the reader R is sent to a desired printer P within the network for image recording. 50°51 is LCD 5x
The 7-dot matrix display has 20 digits each. Guidance (recording size, destination, image processing mode, etc.) is displayed from the machine on these displays 50 and 51. The selection is made using keys 41 to 48 arranged below. Also, if you do not see the display you intended among the guidance, press ETO SET RAKI-9a to change the display contents of the guidance to be selected one after another, so that the display you intended is not displayed. Just keep pressing until it appears.

The number of copies display 52 is a 7-segment LED and is provided separately from the liquid crystal displays 50 and 51 so that it can be seen from a distance. 55 is a group of ten keys and is used for numerical entries such as the number of copies, destination dial, number of copies to be sent, trimming coordinates, movement coordinates of the reproduced image, etc. Completion of entry is indicated by the rEJ key. 54 is a start key, and when the 1μ button is pressed, the image is output in binary, and the 141L button is a halftone copy instruction button, which outputs an image expressed in 32 gradations using the dither method. . 15a is a stop key for stopping the copying operation.

Next, referring to FIG. 4, an overview of the printer P will be described. 26 is a power switch. The bit-serial image signal is input to a laser scanning optical system unit 25 of the printer. This doo unit 25 is a semiconductor laser, collimator
It consists of a mirror lens, a rotating polygon mirror, an Fθ lens, and a tilt correction optical system. The image signal from the reader is applied to a semiconductor laser and undergoes electrical-to-optical conversion, and the diverging laser light is converted into parallel light by a collimator lens, and is irradiated onto a polyhedral mirror rotating at high speed.
Scan to. This polyhedral mirror is rotating at a constant speed of 2600 rl)m. During scanning, the width is about 400 mm, and the effective image size is 297 mm (A4 horizontal size). Therefore, the signal frequency applied to the semiconductor laser at this time is approximately 20
MHz (NRz). Laser light from this unit is incident on the photoreceptor 8 via the mirror 24.

For example, this photoreceptor 8 has three layers: a conductive layer, a photosensitive layer, and an insulating layer.
Consists of layers. Therefore, a process component stock is located thereto which allows imaging. 9 is a front static eliminator;
10 is a front static elimination lamp, 11 is a primary charger, 12 is a secondary charger, 13 is a front exposure lamp, 14 is a developer, 15 paper feed cassettes, 16 is a paper feed roller, 17 is a paper feed guide, 1
19 is a registration roller, 19 is a transfer charger, 20 is a separation roller, 21 is a conveyance guide, 22 is a fixing device, and 23 is a tray. The speed of the photoreceptor 8 and the conveyance system is 180 mm/8.theta.C, which is the same as the forward path of the leader. Therefore, when copying using a combination of reader R and printer P, the speed is 3 on A4 paper.
The number of sheets per minute is 0. Further, the printer P uses a separating belt on the front side to separate the copy paper that is in close contact with the photosensitive drum 8, but because of this, the image corresponding to the belt is missing. If a signal is added to that amount, the toner will be developed, and the separation belt will be stained by the toner, which will also stain subsequent sheets of paper. The video electrical signal for print output is cut at the minute svttt.

Also, if toner adheres to the tip of the Corby paper, when it is fixed, it will wrap around the fixing roller 2 and cause a jam.
Similarly, the electric signal is cut off on the reader side so that the toner adheres to the leading edge of the paper by the width of 2111111.

As mentioned above, at station A, the reader R shown in the second figure and the printer P shown in the fourth figure are connected by an electric cable, and as far as the cable allows, for example, the reader R can be placed on top of the printer P. Or you can freely arrange them side by side.

FIG. 5 is a block diagram showing an example of the circuit configuration of the reader R. 1-1, 1-2 are the CCDs shown in the first diagram, and 53 is the CC.
34 is a COD driver circuit that performs standard processing on the D drive and its output; 34 is a shift memory circuit that performs further processing on the output of the driver circuit 63, such as trimming and shifting magnification;
35 is a data serial/parallel converter for performing protocol (pre-communication) with the printer, and 36 is a microcomputer for inputting and outputting control data to each block via a pass line BU, which has a program ROM and data/RAM. 37 is a sequence driver that controls the optical system movement sequence for sub-scanning, which inputs signals from the home position sensor 37a, the image front detection sensor 37b, and the print start position sensor 570 provided on the movement path of the optical system, and sends signals from the printer side. DC motor 57 (1) for paper feeding, registration, and sub-scanning
, controls the exposure lamp 37θ. Each sensor is composed of a photointerrupter that is activated by the arrival of a light shielding cam provided on the block of the first mirror 7. 38 is the operation unit) 38a is the bus interface for inputting and outputting the corresponding data, 39 is the communication key/display unit) 39a
This is a bus interface that inputs and outputs data corresponding to the .

The inkface signals between reader R and printer P are shown on the right. When connecting directly to printer P without communication function, use connector JR1゜JR2, JR3, JR
4 will be described later on the printer P side connectors JP1, JP2. J
P3. Connect each to JP4. Furthermore, when communicating with the outside, the signals originally going to the connectors TR1, JR2, . . . TR3 are once input to the communication interface module 40a, and the signals JPl, , TP2 are also sent from the communication interface 40a to the attached printer P.

It is designed to connect to JP3. Note that rR4 is directly connected to printer JP4. Further, the communication interface 40& is connected to a communication medium through an optical connector JR7,;TR8 or a y-axis connector JR5,1.

Optical connectors JR7, 8 and coaxial connectors JR5, 6 can be selected; for long-distance transmission, choose optical connectors JR7, TR9; for short-distance transmission, choose coaxial connectors JR5, JR6. This has been designed to make it possible.

The BIICAM DKTECT signal BD of JR4 is used to synchronize the output of image data to the printer P with the rotation of the printer scanner (polygon mirror) when the printer P is connected, and is synchronized with the tip signal of each scan line by the scanner. handle.

The BD is output when it is detected that the printer's laser hits a beam detector (not shown) on the side of the drum. VIDEO and CLK are image signals and clocks,
Each line has a width of 72 ns and outputs 4752 pieces. This signal is BEA if a printer is connected.
It is output in synchronization with the M DBTECT signal, and in other cases (transmission to another, etc.), it is output in synchronization with an internal pseudo signal.

■More l! to ENABLE if the image data is 4
This is a period signal in which 752 bits are output. This is also R
Output in synchronization with BAM DETECT or internal pseudo signal. VSYNC is a signal output in synchronization with the output of the image leading edge detection sensor 371) and BFIAM DETECT or an internal pseudo signal, and means that image data will be output from now on. KOF from ■ during traffic lights
Same as tNABLK. PR Engineering NT 5TAR
The T signal is a paper feed command to the printer side. This PR work N
The time interval between TSTART and VSYNC is determined in consideration of the variable magnification and the trimming area. PR Engineering NT l
[fiND is a response signal from the printer P side, which is issued when the trailing edge of the copy paper leaves the photosensitive drum and rides on the conveyor belt, indicating that the printing operation has ended. This is issued by detecting the completion of copy paper separation or by sequence timing. ABX CONNICT
The signal is communication interface module 40! Indicates that L is connected. When a communication interface module is connected, this terminal is connected to GND within the module, thereby activating communication. PR engineering NTFliRC0NNEICT signal is PR engineering N
TI! ! This is output when R is connected, and this terminal should be connected to GND on the printer side. Thereby the υ print is activated.

S, DATA, S, CLK, C8CBUEIY
, PSCBUSY is a serial signal line for carrying out a protocol between the reader R and the printer P (permitting transmission between the two, exchanging information such as signals, etc.) during image recording. That is, B, DATA, S, and CLK are 16-bit protocol data and a clock, and all are bidirectional lines. CEIC' BUSY is output when the league R side outputs data and a clock to the line, and PSCBUSY is output when the printer P side outputs data and a clock to the line. Therefore,
These lines indicate the transmission direction of S, DATA and S, CLK. The center of control of the reader unit is the microphone and the CPU in the computer 36. The role of this CPH is to control keys/displays,
Sequence control, fiber optic communication protocol, printer protocol control, and various counters in discrete image processing circuits are given calculated values according to image processing instructions from keys/displays. is to preset. COD Drino (35 is 2
To drive two CODs, the power supply and timing are changed to CCD1.
-i.

1-2, and receives a photoelectrically converted serial signal of the original image from the COD according to the timing, increases the accuracy [1], performs analog-to-digital conversion, and binarizes it. be. The shift memory 34 converts the two series of binarized image signals for each of the two CODs into one serial signal without overlapping, and converts it into a single serial signal with 4752 bits per line.
The various individual converters 35 mentioned above, including the O signal, CI, and K, convert the serial signals for the protocol with the printer into parallel signals and interface with the CPU, which can be directly connected to the CPH pass line. The sequence driver 37 has built-in interfaces for three sensors installed on the optical system, a fluorescent lamp drive circuit for the light source, a drive circuit for the sub-scanning DC motor, and a PLL circuit for speed control. ) (The interfaces 38 and 39 are the operation keys shown in Figure 6 and the 5 x 7 dot 20-digit liquid crystal display (circuit and CPU pass line B).
This is an interface with the US. 30 k', to
1't 1M unit inputs commercial power from the plug 31 and supplies DC power to drive the DC controller 60, each driver, etc.

Further, MSW is a sleep source switch shown in FIG. 2B is a power supply unit, which inputs commercial power from plug 29.
24cm DC power for each block drive.

Outputs 5V and 15V. Further, MSW is the J4 source switch 27 shown in the second figure. FIG. 6 shows a circuit block of the printer unit shown in FIG. 4. The center of control of the printer P is the DC controller 60, in which the CPU controls the sequence, the optical fiber F, which is used by the reader R or the printer P alone.
Communication with the communication interface module 401L, startup control of the scanner 62, and beam light from the detector 61 caused by the laser lighting 63 are performed during external communication via the .
Dichiku) Performs BD double signal detection, etc. Leader R
The direct connection with is made via the connectors JP1 to JP4 as described above. JP2 and JP3 are the clock CLK and the image data ViDEO generated by the reader R at an instantaneous speed of 13.59 MBPS with one line of 4752 t)it. JP4
is a beam detection signal BD, which is a laser beam position detection signal obtained by a sensor 61 obtained by lighting a laser when the scanner is rotated by a DC controller 60; It is set up somewhere. Therefore, if the image data received from the reader R side is given a signal to the laser at a timing delayed by 11 scanning times from the BD, an image synchronized with the copy paper can be generated.

Next, signals related to Jp1 will be explained. , VTDEOEN
ABLE indicates the valid period of the KO and CLK signals from ■.

Therefore, 47521)it (6VEIYNC, which is active while the i number is being output, is a signal synchronized with the reader's image tip sensor 71), and from this point on, BO, CLK from ■ and KOInNABLFl! from ■! means that is output. This signal is also input to the DC controller 60, and the DC controller 60 functions to rotate the registration roller in synchronization with VSYNC. This synchronizes the leading edge of the copy paper and the image data. PR engineering NT 5TART is the paper feed command signal, P
R engineering NT END is a signal indicating that writing for one page has been completed on the printer side, PRINTRF! ADY means that print preparation is complete, but it does not mean that the data can be received immediately. That's PR engineering NT ENABLE
Indicated by PRIN'lF! RCONNECT
indicates that the PR NTFiR is connected, and the PR
Engineering NTERPOWKRRFiADY is a power switch MS
This indicates that W is activated to turn on the power to the printer P, and that the CPU in the printer P has completed initialization. 1A
DFiRPOW1! IRRII! ADY indicates that the reader R is also powered on and that the CPU in the reader has completed initialization. S, DATA, S, CLK,
C3CBUSY PE5OBUSY is a communication signal with the reader or communication module 40a. The function of the synchronization memory interface 2 is that it receives FiO from the DC controller rather than V from the reader.Bl! JAM D
]l[1 In synchronization with the TECT signal and at a speed matching the rotational speed of the scanner, mO is pumped out from V and given to the laser driver via the DC controller.

FIG. 7 shows the configuration of each station in the network shown in the first diagram. As described above, station A has reader R and printer P, and station B has only printer P. Still, station C has only reader R.

F is an optical transmission line such as an optical fiber, and each station is equipped with the aforementioned communication module 4 to enable information exchange.
0a is provided. There are two communication modules: a communication module A for the station, which is equipped with a reader R and has a communication command tank within the network, and a communication module A, which is equipped only with a printer P, and is equipped with a reader R, and a communication module A that is equipped with only a printer P, and is capable of communicating according to the image information sent to it. This is a communication module B for a subordinate station that performs recording operations. In other words, communication module A has the function of giving commands to other stations in response to transmission requests from users, and communication module B controls operations in response to input command information (command information). It has only the function of

Station A, which has both a printer P and a reader R, and station C, which has only a reader R, have a communication module A in the reader R. Furthermore, station B, which is equipped only with printer P, is equipped with communication module B.

Communication modules A, B are connected to optical fiber F via transceiver module 7.0.

This transceiver module 70 is an optical-to-electrical converter (0
It has an electric-to-optical converter (Elo) and a built-in switch that directly connects the input and output.

Further, a backup battery 72 is provided in parallel with the device power supply 71, and the transceiver module Z is powered by the battery 72.

It supplies power to the O/Ei converter, Ei10 converter, and electronic switch in the internal switch under predetermined conditions. That is, when the device (reader, printer) is powered on in the normal state, the transceiver module 70 is powered by the constant voltage power supply (Pa) 71;
When the device is powered off, power is supplied from the battery 72. However, when power is supplied from the battery 72, the electronic switch is closed and the output and input of the optical fiber F of the transceiver module 70 are directly connected. Therefore, even if the device current is cut off for some reason, the loop line of the system is secured. This backup battery 7 is used when communicating information between stations.
2 is integrated with a transceiver module 70 and a communication interface module 40a.

At station A, 73 is a connector J that connects the communication interface module /l/A and the printer P.
Printer side connectors JP1 to JP4 shown in FIG. 6 are connected to this connector 75 by M1 to JM4. That is, when communication is not performed, the printer side connectors, TP1 to . T.P.
4 is directly connected to the control circuit 73 by the connectors JR1 to TR4 of the reader R, but if it has a communication function and has a communication module A, it also sends signals to the printer P installed in parallel via the communication module A. communicated.

In station B, when recording image information transmitted by the optical fiber F using the printer alone, the connectors JP1 to JP4 on the printer P side are connected to the connectors TMI to JM4 of the communication module B. , performs image recording based on the image information supplied therefrom.

Station 0 has roughly the same configuration as reader R of station A, except that printer P is not connected to the connector of communication module A. In addition, if necessary,
It is also possible to connect a printer P and provide the same functions as station A.

The information transmitted from the transceiver module 70 via the optical fiber is command data (OoMMAND DA).
TA), print start signal (PR NT 5TART) which is a paper feed command to the printer, encoded image data (MO from V) and vertical assistance signal (VSYN).
O). The flow of information on the loose optical fiber F is unidirectional as shown by the arrow, and physically flows through one optical fiber cable. Therefore, when outputting information, it is encoded using the Manchester (MANOHiTffiR) method that combines information and clocks within the communication module so that all information is handled synchronously within the control circuit 73 and the communication module using the corresponding stone clock. is output. Further, a signal input through an optical fiber is separated into information and a clock by a decoding circuit within the communication module.

FIG. 8 shows the configuration of the transceiver module 7o.
2 is the backup battery mentioned above, and the battery 72
The power of D(,!-Do converter 81 is inputted to D
The C-DC comparator 81 outputs ±5V even if the device power is cut off.

This ±5v output is supplied to the O/Fli converter 82 and +
The SV output is provided by the fi10 converter 83 and the Nant gate circuit (
NAND) 84.85.

The electronic switch described in Fig. 7 is this gate circuit 2, 3.
This is a block 86 surrounded by a dotted line in the figure. This electronic switch 86 is turned on and off by the main unit (reader,
Transparent (TRANsPA) from
RF! NT) signal. In other words, when the main unit is not powered on or a power outage occurs, this transparent signal line 87 is in an open state, and the input of the gate 84 becomes a high level (IQ), and the Nant gate 84 receives the electrical signal from the OA converter 82. It is transmitted to the Nandts gate 85. At this time, the signal line 88 to the Nandts gate 85 is also at H level, so this electrical signal also passes through the Nandts gate 85 and is input to the converter 83 via the line 89. In this way, When the main unit is powered off, a signal is directly transmitted from the O/EL converter 82 to the E10 converter.

When importing the above four types of information, PRIN
T EITART, VSYNO, vzDgo o 5
Category 3) When is information? -cr) TRANEIPARF
! The NT ff4 No. 87 wo J (v Hell is directly connected to the image quality converter 6β and ≠ in terms of signals, and is also taken in to itself via the signal line 90.The reason is that
All devices connected by the fiber optic line should be able to simultaneously capture the above information and enable repeat communication.

On the other hand, when taking in OOMMAND DATA, the signal line 87 is set to L level so that the information is not transmitted from the converter 82 to the Vδ converter 83, and it is taken into its own control circuit via the line 90 and analyzed. , the results are transmitted to the destination station via line 88.

Also, TRAN S: PARE when you are the sender
NT signal 87 to L level, PRINT 5TAR
T, VBYNO.

Each signal from V to FtO is sent out via a signal line 88. Hi, the discrimination between the above four types of information is OOMMANDD.
ATA, PRINT 5TART, and VBYNO are distinguished by the identification code added to the beginning, and V
Therefore, B'6 performs discrimination based on the context of the glot call based on OOMMAND DATA.

FIG. 9 shows the configuration of communication interface module A. In Figure 9, the reader R body (D: '4 Kuta JRI Karano VIDJ!) 091, OLK 92, V
From ll1tOKNABLB 93, VBYNO94,
The signal of PRINT 5TART 95 is input to selector 96 via connector JN1. If there is a transmission instruction from the operation unit provided on the reader R, the OPu (shown in Figure 5) will transmit the TRANSPAR in advance before the above signal is input.
FJT signal 9B'iL level wrong, transceiver module Ay 70 NOT TRANSPARENT
MODE [And make sure to terminate the signal you send. And 5FiLF! which is the selection signal of the selector 96! OT FR97 is AOT engineered VBK. As a result, the signals on lines 91-95 are applied to a modulator 99, and a WO signal and a clock (OLK) signal are generated from one serial V. Furthermore, both VIDEO and OLK tD signals are MANOHESTERFiNO
The signal is converted into a single signal through the ODFiR 100f, and is applied to a line 88 shown in FIG. On the other hand, OOMMAND])ATA output from OPu is set in the 40-bit shift register 101. The contents of the 40-bit configuration are 32 bits of OOMMAND DATA and 8 bits of 400 MMAND identification code added to the beginning of the OOMMAND data, for a total of 40 bits.
It's a bit.

When OPu sets 32-bit COMMAND DATA, data bus line 1151cl: 8-bit line, OPu sets signal line 103, 104.
．． 105.

4 in response to the write command signal 106 and the WO signal.
Set over several times. After the fourth set is completed, the shift register 101 performs the shift operation 40 times and inputs the serial signal 107 to the modulator 99. Further, in ENOODERloo, the signal is decoded into a single signal as described above, and the decoded signal is applied to the round/6 converter 83.

On the other hand, the information from the signal line 90 in FIG.
9th illustration MANOHI! 1sTBRDFliOODER
10B, and is separated from V into the BO signal and 0LOOK signal. Then, it is input to the demosimulator 109,
Image team pr: 6 le VIDEO, (3LOOK, EiO1 from V! 1NABIIF!.

V8YNO, PRINT and 5TART case selector 1
14, and also COMMAND DATA
, OOMMAND 0LOOK is shift register 1
1 and is reproduced as an independent signal. Also, further COMM
AND DATA 32-bit section signal,! : L
t:r) aOMMAND AOK signal and WIDE
! A period signal in which 0ENABTJ is continuously output,
In other words, the engineering MA (
)E Generates an ACK signal.

When sending the VIDEO signal from the modulator 99 onto the optical fiber F, it is not always possible to send it out at any time, especially immediately after power is turned on, and in order to prevent signal collision, the information is sent to the transceiver module shown in Figure 8. In other words, it must be confirmed that there is no information on the optical fiber F. Therefore demosulator 10
9 monitors it, and after confirming that the power is on to the reader R body and that no information is flowing to the transceiver modifier, I turn on the ODEMRE.
ADY 110 is generated and given to the modulator 99.

52 Pitno OOM played on demosulator 109
MAND DATA is input to a 32-bit NOR7)-1/register 111. At this time, OPu is Daymod L/
-Evening 109 Kara (7) OOMMAND AOK
K, 1: Since input is applied, immediately after the interrupt, the contents of this register 111 are changed over the signal lines 106 to 106 one after another, and 8 bits each are read out four times in synchronization with the read command signal ORO. Read and analyze the contents.

5M1 to 7M3 are connectors (connector 73 in FIG. 7) for connecting this communication interface module to the printer P. rM1 is connected to TPl (-, 7M2 is connected to Ip2, JM3 is connected to JP3, respectively.R8~-DarR and printer P are installed together, and when performing local copy by jt etc., selector 114 is connected. 5
ELKOT is switched by the P and R signals 116, and the image information input through the lines 91-95 via the connectors JN1-JN3 is sent to the connectors JM1-. Printer P by TM3
to communicate. In addition, when recording image information transmitted from another station by the EIKIJOT PF signal (F'), the EIKIJOT PF signal 117 is used to select the
and transmits the image information sent from the demodulator 109 to the printer PK via JM1 to JM3.

In addition, the selector 114 is switched by the 5KLFiOT PR signal 116 to transmit the image information read by the reader R to the attached printer P, and the EIKL
The selector 96 is switched by the OT F'R signal 97 so that the image information read by the reader R is transmitted to the modulator 99. According to this, the image information read by the reader R can be locally copied by the attached printer P, and at the same time, the image can be recorded by the printer P at a remote location connected by the optical fiber (F).

According to this, it is also possible to monitor in what state the image information read by the reader R is transmitted or not at the same time as the transmission without providing a new monitoring means.

In the communication system of this embodiment, addresses 0 to 9 are arranged in a loop.
You can connect up to 100 stations up to number 9. line? 112 and 115 are 4-bit switches for address setting of individual stations, and the contents are
It is connected to the pass line of the OPu via the port 114 and read by the OPu immediately after power is turned on. By the way, stations connected in a loop can be powered on randomly, and at that time COMMA from multiple stations can be turned on randomly.
If NDs are sent overlappingly, a collision of information will occur on the loop. Therefore, after power on, COMMAND
It is necessary to decide that only one station can transmit. That station is called a hard mask and must be physically set up. The hard mask setting switch is 118. This setting signal is O
Immediately after the power is turned on, OPu tunes this signal and outputs its own hard master station.
Recognize whether it is a Jnihard slave station.

To summarize the above a little more, PRI'NT 5TA
RT.

VIDEO and VSYNO are passed from the O/ffi conversion ia2 to the V6 converter 83.TRANSPARF! N.T.
Each station in the MoDE Kfx unit captures and reproduces the information it passes through as needed, while 00MMANDDATA is transferred from O/E converter 82 to ry5.
NOT TRAN route to converter 86 cut
EIPAREiNT MODF! Inverter 82
The information is input to the 32-bit shift register 111, which is analyzed by the OPu, and the result is set in the 40-bit shift register 101 and output to the W10 converter 83.

The optical fiber line can connect 2 to 100 stations, and each station has a 2-digit BOD switch 11.
The value of 2,113 is the own station number, that is, the identification number (
00-99).

After the power is turned on, there is always one station on the line that has the right to transmit the above four types of information, that is, the transmission right. Setting switch 1 immediately after power on
The station set in hardware in step 15 becomes the master station with transmission rights, but from then on the CO
By exchanging MMANDDATA, this transmission right can be sequentially transferred to one of the slave stations that does not have the transmission right. Thereafter, the mask slave set in hardware by the setting switch 118 is
Masks and hard slaves are called masks, and masks that have transmission rights at a certain point in time and slaves that do not have them are called soft masks and soft slaves.

Immediately after the power is turned on, the OPu initializes the RAM and changes the soft mask to 2-de mask and soft mask according to the mask slave designation in the hardware settings.
The slave becomes a hard slave. Therefore, 1. There must be only one hard mask during the line. After initialization, the soft mask returns to COIJMAN within a specified time.
Always send KODATA from D DATA or V. When this DATA is not input for a predetermined period of time, the soft slave initializes the communication line and
Recovers from errors such as the mask powering down. COMM
With only AND, the soft slave only performs the operation of relaying or importing such data.

The transfer of transmission rights is a specific CO sent from Soft Mask.
This is done via MMAND DATA, and the transfer is done only when a key operation for an image transmission request is performed in the soft slave.

TRANSPAINT IvlOD'F2 becomes
When power is cut off and VIDEODATA, PRINT
It is time to receive 5TART and VSYNO. Therefore, a station with a soft mask always has N
0TTRAIJ8PARE! It is now NT MODB. In FIG. 7, it is assumed that station A is a hard mask and station B is a hard slave. The hard mask is applied immediately after the power is turned on, and the soft mask is applied at predetermined intervals of 00 MMAND DA.
Send TA. At this time, electronic switch 86 (Fig. 8)
is open. The hard slave that received the above 00MMAND DATA switches electronic switch 8 immediately after the power is turned on.
6 is in the closed state, and after confirming that no image information is being sent, the electronic switch 86 is opened.
OMMAND DATA is transmitted from the soft master. The OMMAND DATA is once received by the soft slave, the contents are analyzed, data is added as necessary, and then transmitted to the fire station. If station people use soft masks, OOMMA
ND DATA is from station A to station B,
It then passes through Station A, returns to Station A, and disappears.

On the other hand, pn engineering NTSTART, VSYNCI,
When transmitting image-related signals such as go DATA from v, the soft mask should be set to COMMAND immediately before
This is done after transmitting DATA and thereby closing the electronic switches 86 of all soft slaves, that is, after forming a bypass path. Soft slave electronic switch 86 is returned to the open state by an interrupt from demodulator 109.

FIG. 10 shows the configuration of communication interface module B.

Basically, it is the same as the communication interface module A shown in FIG.
TMj~, has 7M3.

Components with the same numbers as those in FIG. 9 have the same functions.

In the case of communication module A, the CPU in the reader R body is still in charge of all communication protocols, circuit control within communication module A, and protocols between the reader and the printer, but
Since u does not have these functions, CPU u1 is installed in communication module B of the station that only has printer P.
The OPu 120 performs the DC controller protocol of the printer P, the communication protocol between stations, and the circuit control within the communication module B. As a result, 0Pu120 with and 5tati
It has the function of receiving an inquiry from on, asking the DC controller, and transmitting the result according to the command format.

Figure 11 shows command data (C! OMMAND DAT).
A) shows the model. As mentioned above, the command data is 32
This is bit data that is transmitted from a station that has become a soft mask. Command data that is transmitted from a soft master is sequentially transferred between soft slaves connected in a loop, and the data necessary for the soft mask is transmitted. Returns with information added.

When transmitting command data to the loop line, both the soft mask and the soft slave keep their own station's transparent switch (electronic switch 86) open. Therefore, the command data is read by the OPu of the receiving station, undergoes some processing, and then is transferred to the next station.

Furthermore, if the station power is not turned on, the transparent switch is closed and the received command data is directly transferred to the next station without any processing.

As shown in FIGS. 11 (1) to (5), there are five types of command data, where a is the data type at the time of transmission and b is the data type at the time of reception. Note that the blank bits in b are set to the same bits as in a.

The content of the command data is identified by the lower 4 of the upper 1st byte.
It is done in bits. Further, the bit indicated by C in the fourth byte is a 4-check sum pit for detecting errors in the data transfer, and is determined by the following equation using the values set in the upper three bytes.

Checksum bit (com 4th byte) = O-co
m1th byte-com 2nd byte-com 3rd byte FIG. 12 shows a transmission and reception flowchart regarding the checksum.

(IL) This shows how a station of a soft mask transmits command data to the next station.In step S1, the upper 1 to 3 bytes of the command data are first set. Next, in step S2, the top 1 to
The value obtained by calculating the checksum bit from the 3-byte value as described above is set in the 4th byte. In step S3, the command data set from 1 to 4 bytes is sent to the transmission register on the write line. A response to this sent command is then awaited in step 84.

If a response command is input, it is checked in step S5 whether the checksum error pit is on or not, and if it is not on, processing according to the command is performed in step S6, and if it is on, the command is set again. Send.

(b) shows the operation of the station that has received the command, and the operation starts when the command input is judged by the demoshrake 109 and the COMMAND ACK signal is transmitted to the CPU.

In step 811, the command data set in the 32-bit shift register 111 is read into the CPU, and in step 812, a checksum is calculated using the upper 1 to 3 bytes. Stella 7'' 813 determines whether the calculated value obtained in step 812 and the checksum bit set in the fourth byte are equal or not, and if they are equal, there is no error and the checksum error flag is turned off. , if they are not equal, it is assumed that an error has occurred and the checksum error flag is turned on.

In step S14, it is checked whether the current station is a soft mask, and if it is a soft mask, a flag is passed to step S4 of (a). If it is not yet a soft mask, and the checksum error flag is turned on in step 815, the process advances to step S17, and a command to that effect is sent out. If it is not turned on, processing according to the command is performed, and then the process proceeds to step Si7, where the command data is output to the next station.

Return to Figure 11. (1) is the command number [ooooJ
Channel check frame indicated by )' (0Oc
on) and has the functions of checking the line status, confirming and notifying stations connected to the line, transferring and monitoring transmission rights, and recovering from line errors, and outputs at predetermined intervals when in the soft mask state. In the first upper byte, the S bit indicates a connection status set when it is 1. The E bit indicates that the station address is duplicated, and the F bit is set in the checksum bit when a transmission error is detected. M of the lower 7 bits of the upper second byte is the station address area of the soft mask, and when the A bit at the beginning of the second byte at the time of transmission is 1, it indicates that transmission right transfer is accepted. At the time of reception, the R bit still indicates that a transmission right request has been made from the soft slave. The lower 7 S bits of the third byte are the station address, and when the first O bit is 1, it indicates that the station indicated by the date is connected to the line. With this command, the connection status of stations in the network can be easily recognized. (2) is the sleep inhibit command (SICam) indicated by the command number lo 001J,
It has the functions of notifying the start of image data transmission, notifying transfer of transmission rights, notifying the size of the transmitted image, and specifying the destination according to the data at the time of transmission. M in the second byte is the address of the soft master station as described above, and P in the lower three pits of the third byte, which indicates the destination, indicates the paper size.

Note that this command is only a notification and does not particularly require a response, and is received in the same format as when it was sent.

(3) is a slave setting command (SScom) indicated by the command number "ooloJ", and has the function of confirming the connection of the soft slave specified as the destination and setting the number of communication sheets. S
The bit indicates the station number of the destination soft slave, and the ON of the third byte indicates the number of sheets to be transmitted. The A bit in the first byte of data when receiving data indicates that it can be received, R indicates that the soft slave indicated as the destination received it, and E indicates that the station number is duplicated. Show that. The Soft Slave starts the printer's pre-operation upon receipt of lcom.

(4) is a slave confirmation command (SICom) indicated by the command number l-0011J, and has the function of confirming the connection of the destination soft slave and confirming the number of received sheets. S in the second byte of the data at the time of transmission indicates the station address of the destination soft slave. Further, R in the first byte of the uppermost byte of data at the time of reception is a bit indicating reception by a soft slave, and E indicates that the station numbers are duplicated. N in the third byte is a bit indicating the number of sheets received. Visit SOcom
The soft slave that receives the image is released from the image receiving state and can perform local copying.

(5) is an error check command (EOcom) indicated by the command number "o 10 oJ", and has the function of error checking and transparent switch switching instruction when multiple soft slaves are specified as transmission destinations at the same time. The data type at the time is simply setting "0", and the transparent switch is closed at the input of the soft slave ii FiOcom with no error or no transmission. In addition, the soft slave in which the error occurred sets the station address in the second high-order byte, sets the error status in the third byte, and returns. The soft mask repeatedly transmits EOcam until the error flag E in the first byte becomes 0. Local copy is still possible for soft slaves with error status set.

A protocol for communication is performed by exchanging the above five types of command data.

Figure 13 shows a loop network initialization control flowchart.

When the power of the device (printer, reader) is turned on, initialization including communication-related RAM areas is first performed in step 821. Next, in step 22, it is checked whether the station itself is set as the hard master having the first transmission right, depending on the state of the setting switch 118 (FIG. 9). If it is a hard mask, step 82
At step 3, the RAM mask flag is turned on and the transparent switch is closed to complete the initialization. On the other hand, if it is a hard slave, step 824 *After turning off the master flag, step 5251S28 indicates command data input with 007. (Check the input of the MANDAOK signal or the IMAiAOK signal indicating input of image data.

If the 00MMAND ACK signal is input, step 82
In step 6, it is determined whether the command data is 8ICo1n and image data will be input next, and if so, the initialization is completed with the transparent switch closed in preparation for image input. If it is not an image input, the transparent switch is opened in step S27 in preparation for command data input, and the initialization is completed.

On the other hand, if the IMAGIli AOK signal is input, the process proceeds to step 829 and the transparent switch is closed to complete the initialization. In this way, when Hatsrape joins a network that is already communicating, the transparent switch will be activated depending on whether the information flowing is a command or an image, or depending on the information flowing next, so that the station that is in the middle of the communication will operate the transparent switch. It is possible to prevent negative effects such as interruptions in information due to the participation of other parties.

Figure 14 shows the movement of the soft mask within the line, i.e.
3 is an operation control flowchart for transmission right transfer.

In step 831, a check is made to see if there is an image transmission request from the user, and if there is, the process proceeds to Stella 7'' 839 to check whether or not the own station is currently a softmask.It is already a softmask and has the transmission right. If so, the process directly advances to step 843 to transmit the image.On the other hand, if it is not a soft mask, a transmission right request is transmitted to the current soft mask using the aa command in step 6140.If the transmission right is acquired in step 841, the soft mask Set the master flag indicating that the
Image transmission is started at I43. If the transmission right cannot be acquired, the process returns to step 831 and follows the same route.

If there is no image transmission request, the process advances to step 832 to check whether or not the own station is currently a soft mask. If it is not a soft mask, the process directly returns to step 831.

If it is a soft mask, step B'+3 is 00 (
Channel check) Checks whether it is the command transmission timing or not, and if it is the transmission timing, transmits the Ca command. After that, in step 835, the return υ of the CO command is awaited, and if the input command has the transmission right request pin (R) set by another station, step 8
The process advances from step 56 to S37, where the receiver outputs an OO command with bit A set, turns off the master flag indicating that it is a soft mask, and further transmits an OC command.

In this way, the transmission right is transferred using the CO command,
To ensure that there is always only one station with transmission rights in the network.

FIG. 15 shows a control flowchart for error detection. FIG. 15(a) shows error detection at the start of operation of the device. After initialization is completed in step 850, it is checked in step S51 whether or not the own station is a soft mask, and if it is a soft mask, the first timer is started in step S52. An image transmission request is checked in step 853, and if there is a request, image transmission is started in step 857, but if no transmission request is made, the count-up of the first timer is checked in step 854. Once the first timer has counted up, proceed to step 859 with the channel check command (
OOcom) Start the second timer for transmission. If OOcOm is received in step 859 before the second timer counts up, the process advances to step S61 and the error flag E of OOcom is checked, and if the error 7 flag E is not set, the process returns to step 851. On the other hand, OOc
If the older error flag is set in om, it is determined that there is a station with the same station address, and the occurrence of a multiple mask error is detected, and OOcom is retransmitted in step 863, and OOcom is retransmitted in step 850.
Return to and execute initialization.

On the other hand, if OOcom is not input before the second timer counts up, the process proceeds to step 862, where it is determined that a line disconnection error has occurred, and the process proceeds to step 850, where the process restarts from initialization.

On the other hand, if the own station is determined to be a soft slave after the initialization in step 850 is completed, step 855
Proceed to and start the third timer.

If the transmission right is acquired before the third timer counts up, the process proceeds from steps 856 to 857 and the image is transmitted; however, if it is not acquired, the process proceeds from steps 864 to 866, where it is determined that there is no soft mask error, and the process returns to step 850 to initialize the line. .

On the other hand, if the error flag E is set in the input OOaom, it is determined that there is a mask multiple error 7 lag as described above, and the process returns to step 850 to initialize the υ line.

FIG. 15(b) is a flow chart of error detection during command reception and transfer. The OPu is interrupted by the OOMMAND AOK signal indicating input of command data, and this flowchart is controlled. First, the error flag E of the CO command input in step 870
Check to see if it is set, and if it is set, it will be 8.
In step 71, an error flag is further set and command data is output, and in step 872, a third timer is started.

If it has not been set yet, a third timer is started and the process ends.

This method reliably checks for errors such as when a new command is not input within a predetermined time, when the transmission right is not transferred, or when a station with the same station address exists. At the same time, if such an error is detected, the process returns to the initialization routine and restarts from line initialization to correct the error.

As in this embodiment, each station is provided with a transparent switch (electronic switch 86) that bypasses transmitted data. Also, when initializing the communication line when the power is turned on, Mika of one station that is set to hard mask with the hard mask setting switch 118,
In addition to having the first transmission right, the station recognizes the address by the state of SIN≠, which indicates the address (or number) of the own station. Next, the Heart Master opens the transparent switch to finish initialization. Further, if there is a notification that the transmission right has been granted, the initialization is completed with the transparent switch kept closed, and when the image data P is sent, the transparent switch is opened. Therefore, it is possible to avoid collisions on the communication line between commands that are output before one image data, and to enable the image data to be relayed to a plurality of stations.

In addition, in this embodiment, there are two software master stations that can output command data and image data onto the communication line.
There are no more than 1,000 soft masks, and the soft mask is movable. The soft master station also notifies other stations whether or not the transfer of the transmission right is possible, and if there is a request to acquire the transmission right, it will deal with it.

In this way, the soft mask station transmits commands at fixed time intervals, but the soft slave station checks the transmission right request flag of the input command when a transmission request is issued by the user, and if this flag If not set, set the flag and output. Then, it waits for a response command from the softmask, and when it is notified that the transmission right has been handed over, it acquires the transmission right for the first time and becomes a new softmask. In this way, the soft mask having the right to transmit is determined in a pre-emptive priority manner without prioritizing stations, so all stations have the right to act as a mask fairly.

The station that has obtained the transmission right goes to the soft master stand and sends commands at fixed time intervals that have the function of checking the connection status of the stations that make up the communication system and the function of notifying the confirmed connection status. The information is output to the line, thereby transmitting the connection information of the station controller to each station making up the communication system. It is possible to know this without making inquiries for each slave station.

In addition, when transmitting image data, the station that has become a soft mask outputs a command to determine whether the destination printer P is usable or not, and if it is usable, it sends a command to prepare the printer for printing. Instructs a proper start.

After that, the soft mask also uses a command to contact the printer to determine whether or not it is possible to start the printing operation, and only when it is determined that the printer can start the printing operation starts transmitting the image data. In this way, since the image data is transmitted after accurately knowing the operating state of the printer, the image transmission can be performed reliably and without waste.

In addition, the commands output from the softmask are not only related to transfer of communication rights and connection status, but also detect faults in the communication line, and in the event of an error,
By initializing the line or displaying a message to that effect on each station, early recovery from error conditions and early notification can be achieved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a network configuration to which the present invention is applied, FIG. 2 is a diagram showing an example of a reader R, FIG. 3 is a diagram showing an example of an operation section, and FIG. 4 is a diagram showing an example of a printer P. diagram showing,
Figure 5 is a block diagram showing an example of the circuit configuration of reader R;
7 is a block diagram showing the circuit configuration of printer P, FIG. 7 is a diagram showing the internal configuration of the network, FIG. 8 is a circuit diagram showing an example of an electronic switch, and FIG. 9 is a diagram showing the configuration of communication interface module A. , 10th rMId communication M
'f Diagram showing the configuration of interface module B, 1st
Figure 1 is a diagram showing the format of command data, Figure 12 is a flowchart diagram showing a checksum routine, Figure 13 is a flowchart diagram showing initialization control, and Figure 14 is a flowchart diagram showing control of transmission right transfer. , FIG. 15 is a flowchart of error detection control, where A, B, and O are stations, P is a printer, R is a relay 1', 70 is a transceiver module, 72 is a backup battery,
84.85 is a Nant gate, 82 is an O/JIG converter,
83 is a ≠ converter. Applicant Canon Co., Ltd.

Claims (3)

[Claims] (1) In an information transmission system that transmits information between multiple stations, a station that has made a transmission request outputs a transmission right request command, and acquires the transmission right by receiving a request acceptance command from the station that currently has the transmission right. An information transmission system characterized by: (2) An information transmission system for transmitting information between a plurality of stations, which is characterized in that it detects an error in the system and, if detected, initializes the system. (3) In an information transmission system that transmits multiple pieces of information through a loop-shaped transmission path between a plurality of stations, each station has switching means that forms a bypass path that leads to other stations without taking in the information. A station with transmission rights opens the switching means to perform initialization, and a station without transmission rights operates the switching means in accordance with the type of input data to perform initialization. Information transmission system.