JPH08202207A - Device for detecting connection state of optional equipment - Google Patents

Abstract

PURPOSE: To precisely detect the connection state of an optional equipment. CONSTITUTION: This device is provided with a detection means (communication part 7, control part 9) detecting connection states of the optional equipments 5a-5d when power source is applied, a nonvolatile memory 8 storing the connection states of the optional equipments and a means comparing the connection states detected by the detection means with the connection states stored in the nonvolatile memory 8, and as the result of the comparison, the data of that connection exists are written in the nonvolatile memory 8 of a part where the connection state is changed from that no connection exists to that connection exists, and as the result of the comparison, related to the part where the connection state is changed from that connection exists to that no connection exists, a signal of an effect that a communication error occurs is outputted to an operation part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optional equipment connection state detecting device used in a copying machine or the like.

[0002]

2. Description of the Related Art For example, in a copying machine, the functions of the copying machine can be expanded by connecting optional equipment having various additional functions to the copying machine body which performs a basic copying operation. Optional equipment includes, for example, an automatic document feeder, a sorter, a large-capacity paper feeder, and the like.

The copying machine body and these optional devices are
Not only is it mechanically connected, but it is also electrically connected in order to give an instruction from the copying machine main body to the optional equipment and to inform the copying machine main body of the operating state of the optional equipment.

The operation to be executed by the copying machine when a copying start instruction is given to the copying machine depends on whether or not these optional devices are connected. It is necessary to know in advance whether these optional devices are connected.

Therefore, conventionally, a special harness for detecting the connection state between the main body of the copying machine and the optional equipment is provided, or a service person uses a diagnostic mode when the copying machine is installed. The connection state of optional equipment is input from the operation panel and stored in the non-volatile memory provided in the main body of the copying machine.

However, there is a problem that providing a special harness causes an increase in cost, and that inputting from the operation panel in the diagnostic mode is cumbersome to operate.

Further, in Japanese Patent Laid-Open No. 5-116833, it is described that the communication data transmitted and received between the main body of the copying machine and the optional device includes the data indicating the connection state of the optional device for transmission. Has been done. According to the apparatus described in the publication, the connection state can be detected only by the response between the main body of the copying machine and the optional device. Therefore, the above-mentioned problem is solved, but another problem occurs.

That is, in the apparatus described in the above publication, the connection state of the optional equipment is judged only by the presence or absence of the response from the optional equipment. Therefore, when there is no response from the optional equipment, It is not possible to judge whether they are not connected or whether an optional device is connected but a communication error has occurred, and it is not possible to properly display the state of the device.

Furthermore, Japanese Patent Laid-Open No. 4-67162,
As described in JP-A-4-69672, JP-A-4-81864, etc., a communication line such as a telephone line is used to remotely initialize the connection state of the device to a central management device. It is possible to do it, but in this case,
There is a problem that a communication line is required and the load on the central management device side becomes heavy.

[0010]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to accurately detect the connection state of optional equipment.

[0011]

In order to achieve the above object, the present invention provides a detecting means for detecting the connection state of an optional device at power-on, a non-volatile memory for storing the connection state of the optional device, and a connection. Means for writing data with connection to the non-volatile memory of the portion that has detected, a means for comparing the connection state detected by the detection means and the connection state stored in the non-volatile memory, the result of the comparison, And a means for outputting a signal indicating that a communication error has occurred with respect to a portion where the connection state changes from the presence of the connection to the absence of the connection.

[0012]

In the present invention, the connection state of the optional equipment is detected when the power is turned on and compared with the previous connection state of the optional equipment. As a result of the comparison, if the connection state changes from the presence of a connection to the absence of a connection, a communication error may have occurred, and this is displayed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be specifically described below based on embodiments with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an optional equipment connection state detecting device of the present invention. In the following description, a copying machine will be described as an example, but the present invention is not limited to this.

The copying machine main body 1 is an operation section 2 such as a user interface for giving various instructions to the copying machine and displaying the status of the copying machine, an image input section 3 for reading a document and converting it into an image signal, and an image. An image output unit 4 for forming an image on a sheet based on a signal, a communication unit 7 for communicating with a plurality of option devices 5a to 5d connected to the copying machine main body 1 via a line 6, and an option. Equipment 5a-5
A non-volatile memory 8 for storing the connection state of d, a control unit 9 for controlling the overall operation, a power supply circuit 10 for supplying an operating voltage to each unit, and a power switch for controlling the power on / off of the copying machine. Etc. 11 are provided. The controller 9 receives a power-on signal generated when the power switch 11 is turned on and the power of the copying machine is turned on.
Supplied from

Next, the basic operation of the optional equipment connection state detecting device described above will be explained.

Copier body 1 and optional devices 5a to 5d
The communication between and is performed by using the copying machine main body 1 as a master and each of the optional devices 5a to 5d as a slave by using serial communication. Two communication lines are provided, one communication line is commonly connected between the transmission end of the copying machine body 1 and the reception ends of the optional devices 5a to 5d, and the other communication line is The receiving end of the copying machine body 1 and the transmitting ends of the optional devices 5a to 5d are commonly connected.

The communication specifications are as follows, for example.

Communication method: Full-duplex asynchronous data transfer method Baud rate: 4800BPS Data length: 8 bits Parity: Odd stop bit: 1 bit Communication cycle: 100 FIG. 2 shows an example of communication data format.
The communication data is composed of three parts of a control word, data and a check code (BCC), and the control word is composed of an address and a data length. The control word, data and check code (BCC) are called 1 block data.

When the power is turned on, the slaves, that is, the optional devices 5a to 5d are ready to receive data within, for example, 500 ms, and wait for communication data from the master, that is, the copying machine main body 1 side.

The master has a fixed cycle, for example, about 100 m.
Communication data having an address corresponding to each slave is transmitted in s cycles. The communication data for each slave is arranged in series within a 100 ms period. FIG. 3 is an explanatory diagram schematically showing the exchange of communication data between the master and each slave. A, B, C, D in the figure
Corresponds to the optional devices 5a, 5b, 5c and 5d.

The slave receives the communication data from the master and checks the address in the control word.
When the received communication data is the communication data addressed to itself, after receiving the one block data from the master, the transmission to the master is started within a fixed time, for example, 1 ms. Communication data from the slave is sent to the master side, and by checking the address in the control word on the master side, it is possible to determine which optional device is connected and what the state of the optional device is. I can know.

However, when a reception error occurs in the communication data from the master, it is not transmitted to the master. The reception error is checked for each byte and for each block, and if any of these errors occurs, it is regarded as a reception error. Check 1 for each byte
Parity error, framing error for each byte received,
This is done by detecting an overrun error. Further, the check for each block is performed by taking the exclusive OR of the BCC data of the last byte and the received data. However, the checking method is not limited to these.

When there is no response from the slave, the master transmits the same data at the next transmission timing, and when there is no response even if the same data is transmitted three times, it is determined that a communication error has occurred. .

Next, the operation of writing the connection state of each optional device in the non-volatile memory 8 will be described with reference to the flowchart of FIG.

When the power is turned on (step 101),
The optional equipment to be inspected is selected (step 102), and the counter value CNT for receiving error count is selected.
Is reset to 0 (step 103). Next, communication data is transmitted from the master to the slave (step 104, see FIG. 3), and then it is determined whether communication data corresponding to this transmission has returned from the slave side (step 105). If there is a response from the slave, it means that the optional device is connected, so the address of the communication data from the slave is checked to determine which optional device is connected, and the nonvolatile memory is detected. The information indicating that the optional device is connected, that is, "1" is written in the corresponding part of the optional device (step 106).

If there is no response from the slave in step 105, the same data is repeatedly transmitted three times (steps 104, 105, 107 and 108), and if there is still no response, it is decided that there is no connection (step). 10
9).

Next, the connection state of the optional equipment detected when the power is turned on is compared with the connection state of the optional equipment already written in the nonvolatile memory 8 (step 110). FIG. 5 schematically shows the connection state of the optional equipment stored in the non-volatile memory 8, where “1” indicates the state in which the optional equipment is connected, that is, there is a connection, and “0”. Indicates that the optional device is not connected, that is, no connection is made. In the example of FIG. 5, four optional devices out of the five connectable optional devices are connected. As a result of the comparison, if the connection state changes from the presence of a connection to the absence of a connection, a communication error may have occurred, so a communication error message is output to the operation unit 2. The cause of the communication error may be that the optional device is being removed or that the connector that connects the main body of the copying machine and the optional device is disconnected due to some cause, so the operation of the copying machine is prohibited. Then, as a communication error message, a message asking for confirmation as to whether or not the option device withdrawal process as shown in FIG. 6A is displayed (step 111). If the withdrawal process is selected (step 112), information indicating that the optional device is not connected, that is, "0", is written in the corresponding portion of the nonvolatile memory.
Is written (step 113) and withdrawal processing is performed. If the withdrawal process is not selected, then Fig. 6 (b)
A message indicating that the connector is disconnected is displayed, and a message instructing to reconnect the connector and turn on the power again after the power is turned off is displayed (step 1).
14).

[0029]

As described above, in the present invention, the past connection state of the optional equipment and the connection state of the optional equipment when the power is turned on are compared.
With a simple configuration, the connection status of optional equipment can be accurately determined.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an optional device connection state detection device of the present invention.

FIG. 2 is an explanatory diagram showing an example of a communication data format.

FIG. 3 is an explanatory diagram schematically showing transmission and reception of communication data between a master and each slave.

FIG. 4 is a flowchart showing an operation of writing a connection state of each option device in a nonvolatile memory.

FIG. 5 is an explanatory diagram schematically showing a connection state of option devices stored in a nonvolatile memory.

FIG. 6 is an explanatory diagram showing an example of an error message when a communication error occurs.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Copier main body, 2 ... Operation part, 3 ... Image input part, 4 ... Image output part, 5a-5d ... Optional equipment, 6 ... Line, 7
... communication section, 8 ... nonvolatile memory, 9 ... control section, 10 ... power supply section, 11 ... power switch

Claims (1)

[Claims] 1. A detection means for detecting the connection state of an optional device when the power is turned on, a non-volatile memory for storing the connection state of the optional device, and writing the connection data to the non-volatile memory of the part where the connection is detected. Means for comparing the connection status detected by the detection means with the connection status stored in the non-volatile memory, and as a result of the comparison, a communication error occurs in a portion where the connection status changes from the presence of connection to the absence of connection. And a means for outputting a signal to the effect that an error has occurred, and an optional device connection state detecting device.