Serial data communication system having simplex/duplex interface

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT System Overview Machine Description Master/Area Communication System MACS Optical Link MACS I/O Instructions and Operational Overview TABLE 1 Simultaneous Area Operation Status Read and Write Commands TABLE 2 TABLE 3 TABLE 4 Master Controller Master I/O Interface Parity Generator Clock Generator Shift Controls Address Decoder Status Input and Output Control Interrupt Flip-Flop Area I/O Interface Area Controller Operation Subject Port Structure Area Microprocessor and Interface Pseudo-Interrupt Operation TABLE 5 TABLE 5A Machine Clock Interrupt Real Time Interrupt Software Description and Organization State Checker TABLE 6 Interrupt Handler Paper Path Area Controller TABLE 7 RDH/ADF Control Console Controller 8 TABLE 8 RDH/Platen Servos Controller 10 TABLE 9 Master/Servo Software Communications TABLE 10 Phase Lock Loop Control Servo Controller Software Process Controller 12 Master/PCR Software Communication TABLE 11 TABLE 12 PCR Software BACKGROUND OF THE INVENTION 1.
Field of the Invention The invention is in the field of electrophotographic reproduction machines, and particularly those machines controlled by digital computers.
2.
Description of the Prior Art Electrophotographic copying machines are well known within the prior art and typically employ mechanical or combinatins of mechanical and electrical control logic for system control.
Such control means is responsible for maintaining synchronism between the various operational stations of the reproduction machine and to ensure proper operation of the machine during the various operating modes.
These control devices have become increasingly complex as the level of sophistication has increased within the reproduction machine itself.
With the advent of variable magnification machines and color copiers the logical control means necessary to achieve proper synchronization and operation has become increasingly complex and expensive.
Consequently, attempts to obtain efficient operation of these machines has developed utilizing digital computing device controllers which are programmed to carry out a sequence of operational tasks