IOLAN SDS/SCS/STS/MDC User’s Guide, Version 4.5 447
Modbus Remapping Appendix K
K
Introduction
This appendix provides additional information about the Modbus Remapping feature.

Modbus Remapping Feature

The Modbus remapping feature allows a TCP Modbus Master to poll a Modbus slave device and
have the IOLAN translate the UID to a different UID for the slave device. The Master UID has to be
unique on the IOLAN. The Slave UID must be unique on each serial port. The translate rules are
controlled by a file downloaded to the IOLAN.
The following procedure will allow you to use the Modbus remapping feature:
Create a configuration file
zThe file must be called "modbus_remap"
zOne translate rule per line
zThe fields on a line are separated by a comma
Line format for one UID is:
port,master_uid,slave_uid
zport: is the IOLAN port number that the slave is connected to
zmaster_uid: is the UID that the TCP Modbus Master uses
zslave_uid: is the UID that the Modbus slave uses
Line format for UID ranges is:
port,master_start-master_end,slave_start,slave_end
zport: is the IOLAN port number that the slave is connected to
zmaster_start: is the first master UID in the range
zmaster_end: is the last master UID in the range
zslave_start: is the first slave UID in the range
zslave_end: is the last slave UID in the range

Configuring the Modbus UID Translation Feature

1. On the serial port Modbus Gateway, configure Modbus slave. Configuration parameters such as
“UID range” and UID Address Mode will be ignored in this mode of operation