Purpose |
An F-series
or a T100M+ series PLC automatically senses the type of
communication protocols sent to it and responds accordingly. You may however fix the
protocol type so that it does need to check the protocol type before responding. This
command also allows he PLC to be defined as "No Protocol" so that it will not
automatically respond to data that it receives which appears like one of the supported
protocols. This may be important in some applications in which the PLC serial port is used
purely to receive incoming data via INCOMM and INPUT$ and you do not want it to respond to
some data that appears to it as a valid communication protocols This is also useful for
implementing users own communication protocol without worrying about conflict with
the existing protocols.ch= 1, 2 or 3
(COMM port number)
mode =
0 - Auto sensing (default mode)
1 - Fixed at RTU mode
2 - Fixed at EMIT mode
3 - Fixed at MODBUS ASCII mode
4 - Fixed at OMRON C20H protocol mode
5 - Fixed at NATIVE host link command mode
10- No protocol. (For creating user own custom protocol.
IMPORTANT:
- Please note that if you set the protocol to other than the "Native"
(mode=5) or "Auto" (mode=0) that serial port will no longer respond to commands
from TRiLOGI and you will encounter "Communication Errors" when you try
to perform any communication using TRiLOGI with that serial port. You can still use the
other unaffected serial port (e.g. COMM3, RS485) that support host link commands.
For M-series PLCs with firmware revision r42 or above and all F-Series PLCs, setting the
protocol mode to NATIVE (mode=5) disables support for point-to-point communication. Also,
wildcard FCS (i.e. 00) is not allowed in multi-point format in this mode. This is to
ensure the maximum data integrity by accepting only command that are fully formatted with
correct FCS error check. Note that it means the TRiLOGI's "Detect ID"
function will not work since the PLC with protocol mode =5 will not respond to
point-to-point protocol "IR*". You will have to manually enter the ID into
TRiLOGI login dialog box to communicate with the PLC.
To regain communication with the serial port that has been changed by SETPROTOCOL
command, you will have to execute another SETPROTOCOL function that set it to mode 0 or 5
(assuming it has been written into the program), or you must reset the controller by
turning OFF the power and then ON again. If you execute a SETPROTOCOL using the 1ST.Scan
then you must turn on DIP switch #4 before powering up the PLC so that the SETPROTOCOL
command will not be executed and you can regain control of the PLC using TRiLOGI.
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