| 摘要 |
PROBLEM TO BE SOLVED: To immediately resume communication with a remote terminal device at a return from an error when high-order communication is intercepted by the error or the like in a PLC system which controls a plurality of remote terminal devices. SOLUTION: This programmable controller system has a programmable controller having a communicating function, and the remote terminal devices having communication units and I/O units. The communication unit of the remote terminal device has a normal communication state of carrying out I/O refresh processing with the programmable controller and I/O refresh processing with the I/O unit, and an idle state of carrying out only the presence confirmation of the connected I/O unit without transmitting/receiving I/O data, and changes between two communication states of the normal communication state and the idle state, based on predetermined conditions. COPYRIGHT: (C)2007,JPO&INPIT
|
