Copying system with a dual trunk serial communication system using an acknowledge line

• US 5,163,137 A
• Filed: 05/11/1990
• Issued: 11/10/1992
• Est. Priority Date: 10/29/1987
• Status: Expired due to Term

• Current Assignee: Mita Industrial Co., Ltd. (Kyocera Corporation)
• Original Assignee: Mita Industrial Co., Ltd. (Kyocera Corporation)
• Inventors: Amakawa, Katsumi, Yamamoto, Haruo
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): Pollack, Caleb
• Application Number:
  US07/523,281
• Time in Patent Office: 914 Days
• Field of Search: 371/33, 371/62, 371/16.4, 364/200 MS File, 364/900 MS File, 395/800, 355/200, 355/204, 355/205, 340/825.06
• US Class Current: 710/106
• CPC Class Codes: G06F 13/4269 using a handshaking protocol, e.g. Centronics connection

Abstract

An interface system for a copying system, wherein a frame of transmission data employing a serial communication between a copying machine main body and peripheral devices thereof comprises an address block, a data block and a checksum data block, an optional device corresponding to an address transmitted from the main body transfers data to the main body when the data received coincides with checksum data obtained in the device based on the received data and the transfer of the data is complete when the main body confirms that the transmission address coincides with the transferred data, and when the transferred data is not returned from the optional device or the coincidence is not confirmed, it is determined that a transmission error occurs and data is transmitted from the main body again, whereby reliability of transmission is improved.

Claims

1. A copying system comprising:

a) a main body which performs a copying operation;

b) a plurality of auxiliary means for executing operations in conjunction with the copying operation by said main body;

c) primary control means for controlling the plurality of auxiliary means by generating a control signal, the control signal including an address block representing a designated auxiliary means and a command block representing a requested operation for the designated auxiliary means, the two blocks being arranged in series;

d) connection means for connecting the primary control means to the auxiliary means to allow signals to flow therebetween, the connection means including a single main line portion and branch line portions for connecting the auxiliary means to the main line portion, said main line portion further comprising a single bus through which the address block and the command block of the control signal are transmitted to each of the auxiliary means;

e) each of the auxiliary means including;

i) control signal receiver means for receiving the control signal from the primary control means,

ii) means for ;

A) discriminating if the control signal from the control signal receiver means is a signal designated for the auxiliary means,

B) discriminating whether the control signal receiver means correctly receives the control signal, and

C) controlling operation of the auxiliary means in response to the control signal, and

iii) confirmation signal transmitter means for transmitting to the primary control means a confirmation signal indicating that the control signal receiver means correctly receives the control signal; and

f) the primary control means including control signal transmitter means for transmitting the control signal to each of the auxiliary means, and confirmation signal receiver means for receiving the confirmation signal from the auxiliary means, said main line portion including a control signal main wire line and a confirmation signal main wire line, each of the branch line portions including a control signal branch wire line and a confirmation signal branch wire line, the control signal branch wire line and the confirmation signal branch wire line being connected to the control signal main wire line and the confirmation signal main wire line, respectively.

2. A copying system according to claim 1, wherein the primary control means further includes means for checking whether the confirmation signal is received for a predetermined time, and for determining that the primary control means has failed to transmit the control signal when the confirmation signal is not received for the predetermined time.

3. A copying system according to claim 1, wherein the primary control means further includes processor means for checking whether the confirmation signal is received for a predetermined time, for commanding the control signal transmitter means to transmit a control signal when the confirmation signal is not received for the predetermined time, for counting the number of transmissions of said control signal, and for judging that a maloperation occurs in one of the auxiliary means and the connection means when the confirmation signal is not received after a predetermined number of transmissions of the control signal.

4. A copying system according to claim 3, wherein the processor means judges that a maloperation occurs in one of the auxiliary means and the connection means when the confirmation signal is not received after two transmissions of said control signal.

5. A copying system according to claim 1, wherein the control signal further includes a checksum block representing check data in series form.

6. The copying system of claim 1 wherein said plurality of auxiliary means includes an automatic document feeder, a sorter, and a copying paper cassette.