Specifications

Appendix 4 1 : n Connection (Multi-drop) App4-3
Notes on Communication Errors
Processing for PLC Failure
• If a communication error/timeout is detected during communications with a PLC, the PLC failure
information is stored in internal system memory addresses $s 114 to 129 of the V7. No further
communication with the PLC is attempted until a macro command is executed or the display
screen changes.
If a communication error/timeout is detected while accessing the [Read Area], the error is
processed in the same manner as for 1 : 1 connection.
• Using the macro command RECONNECT, communications can be resumed without the display
screen change.
[RECONNECT]
In the case of a multi-drop connection, communication with the port (specified with “F0”) that
caused the failure is resumed once.
Usable Devices
RECONNECT F0
When communication is resumed, the failure information is cleared from the system memory
($s114 to 129).
With Internal Memory Set For [Read Area], [Write Area], and [Calendar]
• In the case that the internal memory is set for [Read Area], [Write Area] and [Calendar], no initial
connection check is performed, and calendar information is read when the V7 series establishes
communications with the PLC for the first time. A communication error does not occur on the V7
series if a timeout is detected while accessing to the PLC.
Supplemental Information:
Internal system memory
The internal system memory is the one for the V7 series system.
Internal
Memory
PLC Memory Constant Memory Card
Indirect
Designation
F0
F0
0 to 255 Resumes communication with the desired port.
−1 Resumes communication with all ports.