Serial Plc Links (Cj1M Cpu Units Only) - Omron CJ - PROGRAMMING MANUAL 08-2008 Programming Manual

Serial Communications
Response Timeout Monitoring (Serial Gateway Mode)
FINS transmission source:
CPU Unit:
Serial Gateway
Remote device:
6-3-5

Serial PLC Links (CJ1M CPU Units Only)

Overview
Specifications
During Serial Gateway mode the time is monitored from when the message
converted into the specified protocol by Serial Gateway is sent until a
response is received from the remote device. (The default is 5 s. The setting
range for a user-specified value is between 0.1 and 25.5 s.)
If a response is not received at the serial port within the set time, a FINS error
response is returned to the source of the FINS command (end code: 0205 hex
(response timeout)). If a response is received after the timeout has occurred,
however, the response received for each protocol is discarded and a FINS
response is not returned to the source of the FINS command.
FINS command received by CPU Unit
Protocol
conver-
FINS command
sion/trans-
mission
Send in
specified
protocol
Serial PLC Links are supported by CJ1M CPU Units only. They allow data to
be exchanged among CJ1M CPU Units via the built-in RS-232C ports without
requiring special programming. Words are allocated in memory in the Serial
PLC Link Words (CIO 3100 to CIO 3199). RS-232C connections can be used
between CPU Units, or RS-422A/485 connections can be used by connecting
RS-232C-to-RS-422A/485 converters to the RS-232C ports. CJ1W-CIF11
RS-422A Converters can be used to convert between RS-232C and RS-
422A/485.
A PT that is set for NT Link (1:N) communications can also be used together
on the same network. The polled PT uses the network to communicate in an
NT link (1:N) with the polling CPU Unit. When a PT is connected, however, the
addresses in the Serial PLC Link Words corresponding to the PT's unit num-
ber are undefined.
When using RS-422A/485, 2-wire connections, PTs set for NT Links cannot
be used together on the same network.
Item
Connection method
Allocated data area
Number of Units
FINS error response
0205 hex (Response timeout)
Response timeout
Received response is discarded
monitoring time
Receive
Receive
Actual response is received
processing
RS-422A/485 or RS-232C connection via the CPU Unit's RS-
232C port.
Serial PLC Link Words:
CIO 3100 to CIO 3199 (Up to 10 words can be allocated for
each CPU Unit.)
9 Units max., comprising 1 Polling Unit and 8 Polled Units (A
PT can be placed on the same network in an NT Link (1:N),
but it must be counted as one of the 8 Polled Units.)
Section 6-3
Time
Actual response
received after timeout
Specifications
305