Chapter 3 Modbus Emulation - Honeywell CIU 888 Protocol Manual

CHAPTER 3 MODBUS EMULATION

NOTE: Set 1000 ms as TRL/2 field port timeout and Refer to the Configuration Manual
Part No.: 4417589_Rev13
Modbus Emulation
The CIU 888 allows Emerson service tool, i.e. TankMaster Winsetup, to
communicate with Emerson Rex gauges via the CIU 888 using the
Modbus RTU protocol. The CIU 888 acts as a transparent tunnel for
transmitting the Modbus RTU messages between the Emerson service
tool connected to the serial host port (RS-232/RS-485) of the CIU 888
and the Rex gauges connected to the CIU 888.
Any serial host port of CIU 888 can be configured for Modbus
emulation.
For CIU Emulation, perform the following configurations:
Configure host port for Modbus Emulation (See section 3.1)

Configure field port communication settings.

CIU 888 (Part No. 4417584) for more information about the configuration of the
field port communication settings.
Protocol Manual - CIU Emulation
CIU 888 3 - 1