CA1165803A - First fault capture - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The system displays an appropriate two digit fault code if a predetermined push button on the operator keyboard is pressed while a status code is displayed.
When the push button is released, the display returns to the status code. The fault codes identify sources of malfunctions rather than status code remedies for efficient fault diagnosis and correction. In a preferred embodiment, there are approximately ninety fault codes available for display covering recirculating document, machine processor, finisher and special occurrence faults. The capturing of the fault is independent of any clearance. Thus, even after the machine has been restored to a Ready status or cleared of status codes, the most recent first or highest priority fault is displayable.

Description

FIRST FAULT CAPI~URE
BACKGROUND
_ This invention relates to diagnosis in micropro-cessor controlled machines, and in particular to ~he determination of the cause of malfunctions or shutdowns~
It is generally known ~o display instruction or status codes to indicate malfunction or improper or invalid op~ration. U.S. Patent 3,062~061 assigned to the ~ame assignee as the present invention, teaches the use of a fault record and code display to identify fault locations.
Ea~h code generally instructs the operator to perform specific corrective actions related to the sp~cific code to clear the machine for operation. For example, various codes are related to RDH and input operation and machine processor operation including paper paths.
In many instances, however, the ins~ruc~ions or status codes only provide a clearance procedure for a ~alfunction but do not identify the exact source of the malf unction~
It. would be desirable, therefore, to be able to identify the oriyin or cause of the malfunction rather than to merely provide a clearance procedure. In addition, particularity in multiple f ault occurrences, it would be desirable to identify the first fault or highest priority fault occurrence.
It is therefore an object of an aspect of the present invention to provide a new and improved diagnostic system including fault identification.
Further advantages of the present invention will become apparent as the following description proceeds, and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.
Various aspects of this invention are as follows:

,, 1 ~ ~$~03 -la-A method of manifesting the cause of machine malfunctions in a reproduction machine or producing impressions of an original, the reproduction machine having a photosensitive member and a plurality of discrete operating components cooperable with one another and the photosensitive member to electrostatically produce the impressions on support material, in the event of a copier malfunction, said method comprising the steps of:
identifying the particular malfunction by a 0 fault code;
storing the fault code in a temporary register, determining if the fault code is the first fault, storing the fault code in a random access memory location, accessing the contents of the memory location, and displaying the manifestation of the fault.
A method of determining machine malfunctions in a reproduction machine for producing copies, the reprod-uction machine having a controller adapted to identify a cause of a machine malfunction, said method comprising the steps of recognizing the machine malfunction, identifying the machine malfunction by means of a code related to the machine malfunction, identifying other fault codes related to machine malfunctions, identifying the first occurrence of a machine malfunction, storing the code representing the first occurrence of a machine malfunction in a memory location, and displaying a manifestation of the first occurxence code upon request.
A method of determining machine malfunctions in a machine having a control memory and a display, said method including the steps of identifying machine malfunctions by a fault code, and ~ ~ 6~803 -lb-displaying the fauIt code to manifest the cause of the machine malfunction.
Briefly, according to an aspect of the presen-t invention, if a predetermined push button on the operator keyboard is pressed while a status code is displayed, the system then displays an appropriate two digit fault code. When the push button is released, the display returns to the `` ~ 3 6~803 status code. In a preferred embodiment, there are approxi-mately ninety fault codes available for display covering recirculating document, machine processor, finishers and special occurrence faults. The capturing of the fault 5 is independent of any clearance. Thus, even after the machine has been restored to a Ready status, the most recent first or highest priority fault is displayable.
For a better understanding of the present invention, reference may be had to the accompanying 10 drawings wherein the same reference numerals have been applied to like parts and wherein:
Figure 1 is a block diagram of a preferred embodiment of a controller made in accordance with the present invention;
Figures 2a and 2b are schematics of a portion of a controlLer board (CMB) of Figure 1 illustra~ing the microprocessor interconnections;
Figures 3a, 3b and 3c are electrical schematics of a portion of the controller board illustrating the 20 ROM interConnections;
Figures 4a, and 4b are electrical schematics of a portion of the controller board illustrating the RAM interconnections;
Figures 5a, Sb and 5c are electrical schematics 25 of a portion of the controller board illustrating the circuitry for generating various interrupt and control signals;
Figure 6 is an electrical schematic of a portion of the controller board illustrating the select 30 signals generated by various decoders;
Figure 7 is a memory map of the controller illustrated in Figure l;
Figure 8 is an illustration of the control panel portion of the control panel board of Figure 35 1;
Figure 9 is a typical logic interconnection - .
.....
. , of a quantity push button illustrated in Figure 8;
Figure lO i5 an illustration of the functional relationships of various elements of a reproduction machine with the controller board and control panel board illustrated in Figure l;
Figure 11 is an elevational view of a repro-duction machine controlled in accordance with the present invention;
Figure 12 is a detailed elevational view of the recirculating document handler as shown in Figure 11 .
Figures 13 and 14 are a flow chart of first fault recovery in accordance with the present invention;
and Figure 15 is an alternative embodiment of fault recovery.
With reference to Figure 1, there is generally shown a controller lO for a reproduction machine inclu-ding a computer memory board CMB 12, an input board 14, an output board 16, power driver board 18, and a solid state driver board 20 located in a card cage in the reproduction machine. The reproduction machine also includes a control panel board 22 and other not shown boards, for example, a fuser controller board and an automatic toner controller board~ The CMB 12, input board 14, and output board 16 are interconnected through a common bus.
The input board 14 collects and organizes in a byte format up to 72 inputs from machine sensors and switches, readable on command by the computer memory board CMB 12~ The input board 14 includes suitable data selectors and buffers as well as resistor networks for receiving the switch ~nd sensor inputs. In addition, the input board 14 bu~fers external interrupt and trap lines namely, an AC zero crossover line, and a machine clock line.

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~ J ~ 3 The output board 16 receives byte formatted output data from CMB 12 and disperses up to 72 ou~puts directly for outpuks re~uiring less than 300 milliamps of DC drive current or indirectly ~hrough the power 5 driver board 18 and the solid state driver board 20 for heavier loads and for AC loads. In addi~ion, the output board 16 can turn off all outputs upon receipt of an input/output reset signal from CMB 12.
The power driver board 18 controls DC outputs 10 9reater than 300 milliamps drive requirement and also a set of AC loads. For example, the power driver board 18 controls various motors through suitable opto insula-tors and thyristors and various solenoids through suitable transistors. The solid state driver board 15 20 controls various components and minimizes EME noise.
For example, the solid state driver board 20 controls various heaters through suitable rectifiers and ~riacs and certain motors through suitable transistors and triacs. The output board 16 generally comprises suitable 20 buffers, latches and drivers.
The computer memory board 12 includes an Intel 8085 microprocessor 24, (Figures 2A and 2B), 18K bytes of read only memory, ROM 26, (Figures 3A
and 3B), lK byte of random access memory, RAM 28, (Figure 25 4A) interrupt and traps (Figures 5A, 5B, 5C) as shown in Table I, a watchdog timer requiring reset at a period of less than 104 milliseconds, decoders 32 (Figure 6) for memory mapped input/output and an on board LED
for diagnostic purposes.

1 1 6~303 TABLE I
INTERRUPT/TRAP SIGNALS

PRIORITY SOURCE NOMEN- EXT REQ'D
CLATURE
1 Zero Crossover TRAP Ext No

2 Real-Time Clock RST7.5 Int No

3 Machine Clock RST6.5 Ext "Out2"

4 Spare RST5.5 Ext "Outl' *Note: External signals processed through an RC Filter and a Schmitt trigger Figure 7 illustrates the controller memory map.
15 With reference to Figures 2a, 2b, 3a, 3b, 3c, 4a, 4b, 5a, 5b, 5c and 6, microprocessor 24 is connected to a suitable input, output port 36 such as a SCHOTTKY bi-polar 8 bit inputjoutput port, Intel Part No. 8212, read only memory ROM 26, random access memory RAM 28, and decoders 32a-32e. Read only memory ROM 26 comprises several ROM memory chips connected to address lines AOOB through AlOB and one ROM chip 26a connected to address lines A04B through A14B, and a ROM chip 26B connected to the output of ROM 26a and address 1ines AnOB through AC3B. Random access memory RAM 28 comprises a number of RAM chips each connected to address lines AOOB through A09B. The outputs of the ROM chips are connected to data bus ADOO-AD07 through a suitable resistor network 40 and buffers 42. The 30 outputs of ROM 26B and the outputs of the RAM chips are also connected to the data bus ADOO-AD07. The data bus is also connected to the output board 16 and input board 14 through a suitable buff er 44 and resistor network 46.

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' 1 ~ 3 Address lines ~08B-AlSB are connected to pins A8-AlS of the microprocessor 24 through a suitable resistor network 48 and buffer 50. Address lines AlOB-A15B also are connected to address suitable decoders 32A-32E, to produce memory chip select signals NCEO
through NCE7, NCEA through NCED, and NMBO through NMB7. Data lines ADO through AD7 at the microprocessor 24 are connected to the data bus ADOO-AD07 through a suitable resistor network.
With reference to Figure 8, there is shown the operator control console 54 illustrating selection switches and indicators. Upon selection of a particular mode, the appropriate lamps illuminate to indicate selection and the controller 10 will respond by con-trolling the machine for the mode selected.
When an operator selects a particular mode of operation, an indicator lamp is turned on to inform the operator of the mode selected, and the normal copying mode is altered to allow the machine to control the mode selected (e.g. auxiliary tray feeding versus normal main tray feeding).
Each mode selection switch serves a dual on/off function. Pressing a particular switch with the mode "off" will cause the mode to be selected.
Pressing a particular switch with the mode already "on" will cause the mode to be cleared, eliminating the need for an additional mode clear switch.
In the normal copy mode, copy paper is fed froM a main tray for one sided copies. 5ix other modes are available. In particular, pressing an auxiliary paper tray switch 56 will cause the auxiliary paper tray lamp to turn on, and will signal the contrcller 10 to allow the processor to feed from an auxiliary tray.
Pressing the two-sided copying switch 58 will cause the two-sided copying lamp and the copy .
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-- . . --1 1 6$B03 side 1 lamp 60 to turn on and will also signal the controller 10 to allow the processor to automatically make two-sided copies. Selection of this mode signals the controller 10 to allow a document handler, if used, to operate in the two-sided copies mode.
Pressing the two-sided document switch 62, will cause the two-sided documents lamp to turn on, and will also signal the controller to automatically make copies of two-sided documen~s. Since making one-sided copies of two-sided documents is a disallowed mode of operation, selecting two-sided document~ will automatically cause the two-sided copying mode to be selected.
Pressing the copy lighter switch 64 will cause the copy lighter lamp to turn on, and will auto--matically clear the copy darker mode if it was previously selected.
Pressing the copy darker switch 66 will cause the copy darker lamp to turn on, and will automatically clear the copy lighter mode if it was sele~ted.
The normal copying mode output is stacks or offset sets. The stacks mode is defined as a number of copies in the copy output receiving area and each copy is made from the same original. The sets mode is defined as a number of copies in the copy output receiving area and each copy is made from a different original. Pressing the stapled sets switch 68 will cause the stapled sets lamp to turn on, and will also signal the controller 10 to allow the finisher to staple each completed set before depositing it into a lower output tray.
OPERATOR INDICATORS
The "ready" lamp is on, in standby, when the system is ready to go into the print state ~the please wait and see instruction indicators are not on). The ready lamp is also on during the normal system shutdown cycle of manual platen input jobs within .5 seconds after the last required exposure scan of the original on the platen is complete. It can also be on when the system is in a diagnostic mode and is off during normal print cycles and wherein "please wait"
or "see instruction" indicators are on. It also goes off in normal man~lal platen system shutdown cycles if the start print is pushed to restart a new job.
Standby state is defined as any time none of the major subsystem drive motors is energized (RDH, processor, or finisher). It generally means the ready lamp is lit or the "see instruction" lamp is lit. The ~see instruction" lamp is lit in conjunction with the display of predetermined status codes and a malfunction situation exists.
The "please wait" lamp is on anytime the controller 10 detects that the fuser roll is under temperature or the controller detects a ~ault and is in a jam shutdown state. It is also on when the system is in the diagnostic mode and off at all other times.
The see instruction lamp is on when any instruction codes must be displayed to the operator. This indicator will turn on in conjunction with any given instruction code and will turn off when all instruction code are cleared. While the instruction code is being displayed, both the see instruction indicator and the quantity display will blink on and off. This indicator will be off at all other times.
The quantity display 70 ~ill provide different types of information. In particular, if the system is in standby or ready the display 70 indicates the number of sets selected in the offset sets or stapled sets modes and indicates the number of copies selected if system is in stacks output mode. If the system is in a run cycle, the display indicates the number of the copy set being imaged in the offset sets or -,,, '~
' ' '~

stapled sets modes and indicates the number of copies which have been imaged in the manual platen mod~.
If the see instruction indicator i5 illuminated, the display 70 indicates the appropriate instruction code.

5 ~nd finally, if the system is in a job recovery condition with the ready indicator illuminated, the display indicates the number o~ completed sets in process in offset sets or stapled sets output modes or indiçates the n~mbèr of completed copies if the system is operating in the manual platen mode.
A typical interconnection of a quantity selector switch to the computer memory board 12 is shown in Figure g. For example keyboard 72 selection informa~ion is supplied to the controller 10 using lS the following signals: Selection data bit 1, selection data bit 2, selection data bit 4, and selection data bit 8. These signals provide a binary coded de~imal (BCD) input ~o the computer memory board CMB 12.
When a number (0-9) is selected, logic common is supplied to a not shown keyboard decoding circuit via the appropriate push-button. The decoding circuit switches Low those signals which are not required for the appropriate selection. The signals which remain Hign become the "active" BCD inputs to the system.
When any selection data bit signal goes Low, the con-troller 10 senses that a push-button is pressed, and the controller 10 reacts to those signals which remain High.
For example, as illustrated in Figure 9, push button number 5 is pressed (BCD 5 = 1 + 4).
Selection data bit 1 stays HI
Selection data b~t 2 goes LO
Selection data bit 4 stays HI
Selection data bit 8 (H) goes LO~
When the computer memory board CMB 12 receives 5~03 the BCD signals from the keyboard decoding circuit, it provides appropriate output signals, also in BCD
form, to the digital display 70~ The control panel board 22 latches and decodes these signals and displays the appropriate digit in the units position. When, as second pushbutton is pressed, the sequence is repeated and the appropriate digit i5 displayed in the units position and the previous number shifted to the tens position. Further keyboard selections will be ignored by the controller 10 until after the clear button is pressed. The mode selector switches interconnect with CMB 12 in other conventional arrangements.
The ~unctional operation of the controller 10 is illustrated with reference to Figure 10. It should be understood that the controller 10 encompassed the various boards shown in Figure 1, includin~ CMB
12. Controller 10 receives operator made selections 74 and keyboard 72 data, monitors machine conditions with monitor signals 76 and prevents machine operation until conditions are satisfactory. When satisfactory, a ready indication 78 is provided. Upon activation of the start button, 80, the controller 10 controls the operation of the process with signals 82, including a document handler and finisher i~ provided.
The diagnostic control 83 is used for entering the diagnostic mode, enterinq diagnostic programs, and displaying fault codes on the digital display 70.
Diagnostic control is obtained by activating a not shown diagnostic enter switch. The controller 10 detects its input and causes the digital display 70 to indicate "dc". In the diagnostic mode, the tech rep can select five diagnostic programs, namely, component control, processor dead cycle, machine clock test, document handler exercise and controller self test. The diagnostic push button 132 (the unlabeled key 132 on the keyboard) switch has three functions; namely, (1) when the machine is in stand-by and the digital display indicates a status code, the button is pressed to cause the display to show the appropriate fault code, (2) when the diag-nostic mode is selected, the button is used together with the keyboard clear button to enter a specific diagnostic program into the CMB 12 memory, and (3) when the component control diagnostic program is selec-ted, the button is used to enter a specific input selection into the controller memory.
The controller 10 also monitors machine states with monitor signals 76 and the operation oE the various components for example, the clutches, solenoids, power supplys. CMB 12 of controller 10 also receives appropriate count signals 86 and timing signals 84 from machine timing 88 to control and synchronize operation and ac~ivates appropriate billing meters 90. Billing meters 90 comprise 3 separate meters.
In particular, a first billing meter counts the total number of paper feeds made from any of the processor paper feeders, main tray 110, auxiliary tray 112 or duplex tray 120~ A second billing meter counts the total number of stapled sets completed by the finisher.
The stapled sets meter signal is produced by the CMB
12 each time the CMB 12 energizes a not shown staple clutch in the finisher. A third billing meter counts side two copies by advancing one count each time a sheet is fed from the duplex tray 120.
During a machine copy cycle, a sequence of precisely timed events must occur in order to produce an output copy. The sequence starts when the start push button is pressed. The machine timing 88 o most of the reproduction machine elements and the RDH is controlled by a suitable (not shown) optical encoder assembly preferably including a clear plastic disc with 144 equally spaced black sections. The disc is mounted bet~een a light source or LED and a phototransi-1 ~ 0 3 stor driver and the disc is driven by a shaft that makes exactly two revolutions for photoreceptor drum revolution. Upon disc rotation, the light beam from the LED is interrupted by the black sections of the disc. The phototransistor converts the light pulses into electrical pulses and these pulses are the machine clock timing signals 84.
The CMB 12 contains an internal counter that counts the number of machine clock pulses as the disc rotates. A timing reset signal is generated once for every pitch or copy cycle ~2 pitches per drum revolution) in order that the controller timing can be synchronized with the machine timing. The timing reset signal is generated by a switch located on the optical encoder assembly and is actuated once every revolution of the disc drive shaft. The controller counts 144 machine clock pulses every reYolution of the disc.
The machine clock pulses are used for sequenc ing most of the processor events during a copy cycle and also timing of paper travel through the processor f or jam detection. At specif ic times, after a copy cycle has been initiated, a sheet of paper must be at a specif ic point in the paper path. The position of the sheet of paper is monitored by a path, switches and sensors and the timing is monitored by the controller counter. The controller uses this inf ormation to detect if the sheet has arrived or departed at a particular point at the proper time.
In operation, in general, the controller monitors the state of input signals and makes decisions to turn the processor components on and off at the proper time to produce output copies. Processor opera-tion is prevented until certain conditions are met, for example, fuser ready. When all necessary conditions are satisfactory, pressing the start print button will initiate the operation.

1 1 6~03 A 120 hert~ clock input signal is generated by a clock circuit on the power driver board 18. This clock is synchronized with a 60 hertz 24 VAC input and is used in the CMB 12 as a control signal to turn on outputs from the output board 16.
The count signal 86 to CMB 12 is a set counter sensor signal located in the recirculating document handler RDH to be described. The CMB 12 also increments a count internally each time a copy paper feed is scheduled from various machine trays.
The controller 10 also contains a real time clock circuit controlling among other functions, a four minute timer. This timer will automatically be started when the machine is in the standby state and 15 either of the following conditions exist: Ready lamp is on with any mode selected, job recovery condition does not exist and the digital display is displaying any number other than one or "see instruction" is on relating to certain instruction codes.
With reference to Figure 11, there is illus-trated a reproduction machine operating under control of controller 1~.
There is generally shown an imaging station 100 of a pre-collation recirculating document handling 25 unit (RDH) 102. Also shown is an optics system 104 for imaging each document image onto a photoreceptor 106. The photoreceptor 10~ has the normal imaging, development, transfer, stripping, and cleaning stations to develop the document image on the photoreceptor 30 106 with fusable toner material and to transfer that toner image to one side of a copy sheet at a transfer station 108. The trans~erred copy page image is then fused to the copy sheet at the fusing station 111.
Clean (unimaged) copy sheets may be fed into the transfer 35 station 108 f rom either of two copy sheet trays 110 or 112. After the transfer and fusing of the copy --` .
1 1 6~5~03 sheet image has been accomplished on one side, the copy paper output path transports it on transport 117 toward an exit area. However, first it passes by a movable gate or deflector 114. Depending on the position of this sheet deflector 114, the copy sheet will either continue on transport 118, or be temporarily captured and stored in a duplex buffer tray or bin 120.
After the sheets have been duplexed (or if the copier is being operated in a simplex copying mode) the copy sheets exit the copier processor through the output transport 118 rather than being deflec~ed into the duplex bin 120. As illustrated, the transport 118 conveys sheets to the finishing area generally indicated at 115. In particular sheets are conveyed through baffle 119 to offset and drive rolls 121, 122.
A deflector 124 provides for selecting between a catch tray 126 or compiler tray 128. It should be noted that the compiler tray 128 is only required for those machines having a stapler 181. The stapler 181 capa-bility need not be provided in all machines and some aspects of the present invention apply to machines with or without staplers.
~ he tray 120 has a bottom sheet feeder 130 for feeding sheets individually out from the bottom of the tray 120 onto a sheet feeding path toward the transfer station 108 for the transfer of the second (opposite) page image to the second (opposite) side of these previously simplexed copy sheets which were temporarily stored in the duplex bin 120. The sheet feeder 130 feeds sheets from the opposite side of the buffer set from which the sheets are normally being fed into the buffer set by the deflector 114. This maintains the proper page order of the simplexed copy sheets in the duplex bin 120.
By way of one example, assume a single copy set of a five page document set is being provided in 1 ~ 65~03 an duplex mode. After a precount slew, page 4 is first copied on one side of a first clean copy sheet fed from tray 110 or 112 and deflected into duplex bin 120 by deflector 114. Then page 2 is copied onto one side of a second copy sheet and placed on top o the first copy sheet in the duplex bin 120. Page 5 is then copied on a clean sheet fed from tray 110 or 112 and ejected to the offset and drive rolls 121, 122 of finisher area 115. The sheet feeder 130 is then ac~uated to feed out the bottom sheet from the tray 120, (which is the first sheet with page 4), to the transfer station 108 where page 3 is placed on the opposite side of that copy sheet~ The deflector 114 is then moved to its alternate position so that this first sheet, which is now fully duplexed, is ejected from the copier through the offset and drive rolls 121 and 122, rather than returned to the duplex bin 120. The sheet feeder 130 th~n next feeds the second sheet, bearlng page 2, out of the bin 120 and the page 1 image is copied on its opposite side, and this second sheet is likewise ejec~ed from the copier.
While in the above-example the copying system is a n to 1 page order pre-collation copying system with a buffer set of the even pages copied first, it will be appreciated that the present system may also be utilized in a 1 to n order pre-collation copying system, and with either even or odd pages simplexed first.
In the manual platen mode, an original is placed on the platen, a number of copies programmed and tbe digital display is advanced one count by the controller CMB 12 for each paper fed from the main, auxiliary, or duplex copy trays 110, 112, 120, respec~
tively.
In the document handler or sets mode, the digital display indicates sets rather than individual , . .

1 3 ~5803 copies. This is the only mode that requires a count input to the CMB 12. When a set circulation is begun through the document handler, the set counter sensor 128 signal is received at CMB 12. That is, the CMB
12 causes the digital display to advance one count on the first RDH feed of every set. This process repeats for each set circulated through the document handler.
DOCUMENT HANDLER
The recirculating document handler (RD~) 102 shown in detail in Figure 12 is selected by placing a set of documents face up into the input tray 134 defined by paper guide 136. The number of desired copy sets is entered via the control console keyboard 72. When start is pressed, the document handler moves each document starting with the bottom document of the set from the input tray 134 to the platen 100, then returns the document to the input tray. One completed copy set is produced when the last document of the set (top document) is exposed on platen 100 and transported back to the document handler input tray 134. If more than one copy set is requested, the process will be repeated until the desired number of copy sets has been produced. In accordance with the present invention, the document handler operates in three modes: ~1) one sided copies from one sided originals, (2) two sided copies from one sided originals and (3) two sided copiés from two sided originals, a special duplex tray being used in duplex requirements.
The two sided copies push button 58 and the two sided document push button 62 signals are sensed to determine which of the three document handler modes has been selected. Timing reset signals provide ~he timing information to insure that the document handler components operate in synchronism with the processor components.
Preferably, an input tray sensor 138 is used 1 ~ ~S~03 by CMB 12 to determine if documents have been loaded into the document handler input tray 134. The sensor 138 is a two piece sensor consisting of an emittar or light source and detector. During an initial count or slew cycle~ the CMB 12 counts the number of documents contained in the set as cycled by the RD~. The slew cycle is also used by the RDH to cycle originals before a job start to invert originals if necessary~
A set separator or finger 140 separates documents in a set to be copied from those documents that have already been copied and returned to input tray 134. Upon command of the CMB 12, a not shown set separator clutch is energized and the set separator finger 140 rotates and falls onto the trail edge of the top document in the input tray 134. A set counter sensor illustrated at 142 normally produces a first signal with the separator finger 140 located on the document stack. The finger 140 on top of the stack allows ligh~ to be sensed by counter sensor 142.
However, when the top document (last document in the set) is fed, the set separator finger 140 falls through a not shown slot bl~clcing light from the set counter sensor 142 and this signal indicates to the CMB 12 that the last document of the set has been fed.
During document feed, drive is supplied to take away rolls 144 and platen entry drive rolls 146.
The document coming from the input tray 134 is trans-ported by the take away rolls 144 to a wait station 147 including a wait station sensor 148. Upon sensing of a document by wait station sensor 148, the take away rolls 144 are inactivated and the document remains at the wait station 147 until the previous document has been exposed. The document at the wait station is then fed to a platen transport 150. The platen transport 150 is secured to the input tray 134 support frame and includes a document belt 152 supported by I 1 ~5803 suitable rollers for driving a document onto platen 100 .
When a document is about to be conveyed to the platen transport 150, the CMB 12 energizes a not shown platen forward clutch and platen reverse clutch to register a document on platen 100. After the document has been exposed, the platen forward clutch is energized and the document is transported by document belt 152 to a return transport area generally shown at 154 and the next document is accepted from the wait station 147. The return transport area 154 includes e~it drive rollers 156, platen exit sensor 158 and middle drive rollers 160. Platen exit sensor 158 is used by the CMB 12 to monitor document movement off the platen 100 and through the lower portion of the return transport area 154.
If a one s_de original c~ mode has been selected, a not shown inverter gate solenoid is not energized and the document is driven past inverter gate 162 to the upper drive roller 164. The upper drive rollers 164 feed the document passed the input tray sensor 138 to the input tray 134. The input tray sensor 138 provides signals to the CMB 12 to monitor document movement through the upper portion of the return transport 154.
During two sided ~ copying, the inverter gate solenoid is energized, and the documents are diverted by the inverter gate 162 to the lower nip 164 of the drive rollers 166. The document is driven around an inverter baffle 168 until the Iead edge reaches an inverter pad 170. As the middle inverter drive roll 172 rotates, the edge of the document is conveyed from the lower nip 164 to the upper nip 174 of the inverter drive rolls 166 and the inverted document 35 i5 then driven by the inverter drive rollers 166 to the upper drive rollers 164 and into the input tray 1 1 65~3~3 134.
The set counter sensor 142 signal manifests to the CMB 12 that the last document of the set has been ~ed to the wait station. During document handler operation, a not shown document counter located in the CMB 12 counts each document fed. When the set counter sensor 142 signal is sensed by the CMB 12, the number of document feeds recorded by the document counter (representing the number of documents in the set), is stored in memory and the document counter is reset.
The document counter is used to detect if more than 50 one sided documents or 25 two sided docu-ments are present in the input tray 134, whether an odd or even number of documents is present in the input tray in the one sided document two sided copy mode, and if a multifeed (a feed of 2 or more originals at one time) has occurred. The CMB 12 monitors document movement and shuts down the document handler and displays a status code if a document jam or multi~eed occurs.
A fault code indicating the exact cause o~ the fault, is displayed upon activation of the unmarked keyboard 132 button.
ON~ SIDED ORIGINAL/ONE SIDED COPY MODE
After the first document is fed from the wait station 147 to the platen 100, and the exposure scan begins, the CMB 12 signals for the second document to be fed to the wait station 147. In particular, a vacuum transport 178 feeds the bottom document forward to the takeaway rolls 144. The bottom document is fed by the takeaway rolls 144 to the wait station sensor 148. The wait station sensor 148 signals the CMB 12 that the document is at the wait station 147. CMB
12 then provides signals to remove the drive from the vacuum tran~port 178 and takeaway rolls 144. The document is then positioned at the wait station 147.

1 1 B$~03 After the document on the platen 100 is exposed, C~B
12 signals for the second document to be fed from ~he wait station 147.
The document on the platen 100 is fed to the return transport area 154 while the document at the wait station 147 is fed to the platen 100. The document is now positioned on the platen 100 for the start oS the new exposure scan. There were no missed exposure scans, that is, the entire document feed sequence, from wait station 147, to platen 100, took place during the return scan of a not shown exposure lamp.
When a document feed is initiated from wait station 147 to platen 100, the document on the platen 100 is fed to the return transport area 154. The platen exit sensor 158 signals CMB 12 that the document has reached the sensor.
The platen exit drive rollers 156 drive the document to the middle drive rollers 160. The middle drive rollers 160 drive the document to the upper drive rolls 164 driving the document into the input tray 134. The document is now positioned on top of the document stack in the input tray 1340 The sequence of document feed to wait station 147, and document feed from wait station 147 to platen 100 continues until the last document of the set (top document) is fed to the wait station 147. At this time, the set separator finger 140 falls and is sensed by the set counter sensor 142. The set counter sensor 142 signals the CMB 12 that the last document (top document of the set) is at the wait station 147.
If only one copy set is requested, the CMB
12 will inhibit any more document feeds from the input tray 134 and will shutdown the document handler after the last document of the set is exposed and returned to the input tray 134. If more than one copy set is ~ 1 ~5~03 requested, the sequence repeats over again for the next copy set. the set separator clutch is energized to position the set separator finger 140 when the last document of the set i5 exposed and returned to the input tray.
SPECIAL REQUIREMENTS
O One-Sided Original - If there is only one document in the set, the document is transported to the platen 100 where it remains until the number of exposure scans equals the copy quantity selected.
The document is then returned to the input tray 134.
Two One-Sided Originals and One Sided Copies - One exposure scan is missed between set cycles to allow enough time for the bottom document to reach the input tray 134.
TWO-SIDED ORIGINALS/TWO SIDED COPY MODE
After a set of documents is placed in the input tray 134 and the print cycle is started, the inverter gate solenoid is energized. The document handler circulates and inverts each of the documents so that the even side of the documents are ready for copying first. After the recirculation cycle (slew cycle) is completed, the copy cycle begins.
The sequence of operation for document movement and position is identical to the One-Sided Original/
One-Sided Copy Mode. During the initial set run cycle, the document handler registers the even side of the documents on the platen 100 for one exposure scan (copies of these documents are fed into the duplex tray 120)o The documents are changed between exposure scans and are inverted before being returned to the input tray 134. There are no missed exposure scans during document changes.
After the initial even side run cycle is completed, the document handler registers the odd sides of the document on the platen 100 for exposure (the I 1 ~5~3 copies of the even sides stored in the duplex tray 120 are fed to the transfer station 108 at this time).
The documents are again changed between exposure scans and inverted before returning to the input tray 134.
The document handler continues the even/odd exposure cycles until the last programmed set (odd side) is being copied. During this cycle, the documents are not inverted prior to being returned to the input tray 134.
During the slew cycle, CMB 12 also counts the number of documents that are in the set. If CMB
12 senses that there are more than 25 documents in the set, the slew cycle will be halted, and a status code displayed informing the operator to remove the excess documents.
SPECIAL REQUIREMENTS
One Two-Sided Original - If there is only _ one document in the set, the odd side of the document is first registered on the platen 100 for exposure.
The document remains on the platen 100 until the number of exposure scans equals the copy quantity selected (a maximum of 25 copies is allowed). The copies of the odd side are fed into the duplex tray 120. Next, the even side of the document is registered on the plate~ 100 for copying. The copies of the odd side stored in the duplex tray are fed to the transfer station 108 at this time. After the last even copy is made, the document is inverted and returned to the input tray 134 and the document handler shuts down. Note that if less than five copie~ are selected, exposure scans will be missed between the odd side and even side exposure to allow enough time for the first odd copy to reach the duplex tray 120.
ONE SIDED ORIGI~ALS/TWO-SIDED COPY MODE
After a set of documents is placed in the input tray 134 and the print cycle started, the document -- .

.

I 1 ~S~03 handler circulates and counts each of the documents to determine if the set contains an even or odd number of documents This information is used by CMB 12 to determine whether each registered document is an even or odd numbered page. CMB 12 can then properly control the processor paper path. After recirculation, the copy cycle beginsO
The sequence of operation for document movement is identical to the One-Sided Original/One-Sided Copy Mode. Each document, starting with the bottom document, is fed to the platen 100 for one exposure scan and is returned to the input tray 134 after exposure.
However, during the initial set run cycle, the machine 10 only makes copies of the even documents (these copies are fed into the duplex tray 120). There is one missed exposure scan while each odd document is on the platen 100 .
During all subsequent set run cycles, excluding the last one, copies are made of each document (copies Of the even documents are loaded into the duplex tray 120 while copies of the odd documents are placed on the second side of the copies fed from the duplex tray 120). There are also no missed exposure scans during document changes.
During the last set run cycle, the processor only makes copies of the odd documents (the copies of the even side, stored in the duplex tray 120, are fed to the transfer station 108 at this time). There is one missed exposure scan while each even document is on the platen 100.
During the recirculation or slew cycle, if CMB 12 senses that there are more than 50 documents in the set, the recirculation cycle will be halted, and a status code displayed informing the operator to remove the excess documents.
SPECIAL REQUIREMENTS

One One-Sided Original - If there is only _ _ one document in the set, the job will automatically be run as a two-sided original two-sided copy require-ment.
Two One-Sided Originals - If there are two documents in the set, the bottom document will be fed to the platen 100 and remain on the platen 100 until a number of exposure scans equals the copy quantity selected (a maximum of 25 copies is allowed). The copies of the bottom document are fed into the duplex tray 120. Next, the top document is fed to the platen 100 for copying. The copies stored in the duplex tray 120 are fed to the transfer station 108. After the last exposure is made, the top document is returned to the input tray 134 and the document handler shuts down. If less than five copies are selected, exposure scans will be missed between even side and odd side exposures to allow enough time for the first even copy to reach the duplex tray 120.
Three One-Sided Ori~inals - If there are three documents in the set, there will be one missed exposure scan between even side and odd side exposures to allow enough time for the first even copy to reach the duplex tray.
PAPER FEED AND REGISTRATION
The paper feed and registration system accepts copy paper loaded by the operator and delivers it at the proper time to meet the lead edge of the developed image on the photoreceptor surf ace 106 at the transf er station 108. For single sided copies the copy paper is fed from either the main tray or auxiliary tray 110, 112. For two sided copies, the side one copies are Eed from the duplex tray 120. The duplex tray 120 has a capacity of 25 side 1 copies, and is located above the auxiliary tray 112.
The duplex tray 120, a main tray 110 and auxiliary tray 112 have (not shown width and length adjustments guides. These guides actuate suitable switches producing signals to CMB 12 manifesting the paper size the tray is set to receive. If Two Sided Copying is selected, and the duplex tray 120 and the main or auxiliary tray 110, 112 lengths and widths are not set the same, the machine will not print.
After the side 1 copies have been properly positioned in the duplex tray 120, the machine 10 will prepare for side 2 copies by placing a bail bar 180 on top of the copies as illustrated in Figure 11.
The bail bar 180 is placed on top of the copies in order to apply pressure between the copies and the feed belt 130. This pressure causes the friction required for the feed belt to feed copies.
The bail bar 180 is flipped at various time in response to signals from CMB 12 as determined by the job requirement~ For example, jobs with two origi-nals will require that as soon as the even side copy is in the duplex tray 120, the bail bar 180 be flipped and the copy fed out. Bail flip is accomplished by energizing and de-energizing two (not shown) solenoids.
The solenoids cause the bail bar to move in two direc-tions, horizontally from under the stack of copies and vertically above the copy stack.
There are also four special conditions under which the bail bar 180 is flipped, namely, at the beginning of all new copying jobs after the start print button is pushed, after all job interruptions when the sys~em is operatinq in the duplex tray mode and the machine is allowed to complete copies that are in process, anytime the machine processor starts up during a duplex tray mode job recovery situation and the CMB 12 has determined that all copies in the duplex tray must be removed (purge, and during all job recovery cycles, CMB 12 con~roller de~ermines at what point the job shall be resumed and if the bail bar 180 needs to be flipped to re-order the duplex tray.
A bail sensor illustrated at 182 composed of a mirror, phototransistor and an infrared light source (LED~ at the bail bar 180 signals the CMB 12 that copies, blocking light from the LED, are located in the duplex tray 120. When no copies are in the duplex tray 120, the light source emits light that is reflected by the mirror back to the phototransi tor, providing a signal to the CMB 12 that no paper is present in the duplex tray 120. After the bail bar goes through its flip cycle, the light to the phototransistor will be blocked by the copy in the duplex tray.
Only the bottom copy will be fed from duplex tray 120 due to force applied by the belt 130 to the bottom side o~ the bottom copy. All copies above the bottom one will have drag exerted on them by a retard pad (not shown), thus breaking any ~riciton that exists between the copy being ed and the next sheet on top O~ it. This action ensures that only one sheet is fed at a time from the duplex tray 120. The single copy is fed into the nip of the duplex tray drive rolls 184.
The copy that enters the nip of the duplex tray drive rolls 184 is driven to a wait sensor 186, signaling the CMB 12 that a copy has arrived at the duplex wait station 188. The copy remains at the wait station until shortly before the start of the copy scan that corresponds to the sheet that is at-the wait station 184. The copy is then fed into the transport 190 to the transfer station 108.
When a machine is in stand-by and the see instructions lamp is lit, the CMB 12 provides the necessary data bit output to display an appropriate alpha numeric status code. It is generally known to display instruction or status codes to indicate malfunc-tion or improper or invalid operation. Each code instructs the operator to perform specific corrective actions related to the specific code to clear the machine for operation. In a specific embodiment, codes lA-9A are related to RD~ and input operation codes lC-9C and lE-9E relate to the processor operation including paper paths, codes lF-6F relate to finisher and output operation, and code CC is a special instruction.
For example, code lA is displayed when any RDH document jam is detected or enabled after power up if paper is sensed under any of the RDH paper path sensors. The code instructs the oper ator to clear the entire RD~ paper path, remove the original set from the input tray, reorder the originals in their initial order, and reposition the original set in the input tray. The code clears when all RDH coqers are closed, no paper is sensed under any of the RDH paper path sensors and no originals are sensed in the input tray.
In many instances, however, the instructions or status codes only provide a remedy to a malfunction but do not identify the exact source of the malfunction.
Therefore, in accordance with the present invention, the operator or tech rep can display a fault code to more precisely identify the malfunction. This fault code identifies the first fault detected in the machine 10 and more precisely identifies the source of the malfunction.
In accordance with the present invention, if the unlabeled push button 132 on the keyboard 72 is pressed while a status code is displayed, the CMB
12 then provides the necessary data bit outputs to display an appropriate two digit fault code. When the push button is released, the display returns to the status code.
In a preferred embodiment, there are approxi-- 1 J 65~03 mately ninety fault codes available for display. For example, fault codes 3 through 7 cover (3) document failed ~o clear the RDH wait station sensor 148 in time,(4) document failed to arrive at the RDH platen exit sensor 158 in time, (S) document failed to clear the RDH platen exit sensor 158 in time, (6) document failed to arrive at the RDH input tray sensor 138 in time, and (7) document failed to clear the RDH input tray sensor 138 in time.
With reference to the flow charts in Figures 13 and 14 the procedure for storing and capturing first f ault identification is illustrated. For example, there may be a failure of the document in the RDH to arrive at the platen exit sensor. This failure would initiate a fault detection and in turn a ~ault code would be recognized and stored in a temporary register, preferably the B register in the CMB 12. A determination would then be made if the fault was in fact the f irst fault detected. If the fault was the first fault, 20 the appropriate fault code would then be stored in a suitable RAM memory location. If it was not the first fault, the fault indication would be ignored and not stored in RAM location. It should be understood also that specific memory locations could be assigned to second faults or as ~any faults as deemed appropriate to record.
To display the fault code, it is necessary to press the unlabeled push button 132 on the keyboard 72. The display 70 will then indicate a code corres-ponding to a specific fault in particular the firstfault instead of the normal status code display. Of course if the specific RAM location containing a fault code is empty, there will be no display and the procedure will exit. It should also be noted that it is within the skill of the art to display contents of successive RAM locations corresponding to first fault and successive 1 1 6~303 faults.
With respect to Figure lS there is illustrated an additional alternative embodiment of the first fault capture and storage. Instead of or in addition to directly capturing the first fault detected and storing, faults are stored in a fault table for example a table of 14 8 bit bytes. The faults are stored in priority locations and after the detection of the first fault, the table is scanned to identify the fault and store it in the appropriate RAM memory location. In this system, the highest priority f ault is stored in the RAM memory location. Of course in this system the highest priority ault might not necessarily be the f irst f ault.
lS The importance of first fault detection is the ~act that specific status code for operator correc-tion may correspond to several separate fault possi~
bilities. The status code does not convey the precise location of the fault that caused the malfunction.
The status code may be generally used to indicate to the operator the steps that must be taken to restore the copier system to a Ready status, whereas the first fault may be more appropriately used to diag~
nose the cause of the shutdown--either by a tech rep at the copier site or remotely by a phone conversation by the tech rep with the operator.
While there has been illustrated and described what is at present considered to be a preferred embodi-ment of the present invention, it will be appreciated that numerous changes and modifications are likely to occur to those skilled in the art, and it is in-tended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.

Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of manifesting the cause of machine malfunctions in a reproduction machine for producing impressions of an original, the reproduction machine having a photosensitive member and a plurality of discrete operating components cooperable with one another and the photosensitive member to electrostatically produce the impressions on support material, in the event of a copier malfunction, said method comprising the steps of:
identifying the particular malfunction by a fault code;
storing the fault code in a temporary register, determining if the fault code is the first fault, storing the fault code in a random access memory location, accessing the contents of the memory location, and displaying the manifestation of the fault.

2. The method of Claim 1 wherein the step of identify-ing the fault code includes the step of scanning a table of faults to determine the fault having highest priority.

3. The method of Claim 1 wherein there are a plurality of machine malfunction possibilities, each possibility associated with at least one memory location wherein the step of displaying the malfunction includes the step of displaying a manifestation associated with the contents of one of said memory locations.

4. A method of determining machine malfunctions in a reproduction machine for producing copies, the reprod-uction machine having a controller adapted to identify a cause of a machine malfunction, said method comprising the steps of recognizing the machine malfunction, identifying the machine malfunction by means of a code related to the machine malfunction, identifying other fault codes related to machine malfunctions, identifying the first occurrence of a machine malfunction, storing the code representing the first occurrence of a machine malfunction in a memory location, and displaying a manifestation of the first occurrence code upon request.

5. The method of Claim 4 wherein said reproduction machine has a display for manifesting status codes, each status code being associated with at least one of the fault codes, the status codes indicating a corrective action related to the machine malfunction, each fault code indicating the source of the machine malfunction including the steps of first displaying a status code and then displaying a fault code.

6. The method of Claim 5 wherein the step of displaying the fault code includes the step of activating a fault code request during a status code display.

7. The method of Claim 6 including the step of activat-ing an unlabeled push button.

8. A method of determining machine malfunctions in a machine having a control memory and a display, said method including the steps of identifying machine malfunctions by a fault code, and displaying the fault code to manifest the cause of the machine malfunction.

9. The method of Claim 8 including the step of scanning a fault table for the highest priority fault before displaying the fault code.

10. The method of Claim 8 including the step of dis-playing the fault code associated with the first machine malfunction detected.