Honeywell CIU 888 Protocol Manual

CIU Emulation
Part No.: 4417589_Rev13 Protocol Manual - CIU Emulation
CIU 888 1 - 9
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1.3.2 RS-485 multi-drop configuration
In case of an RS-485 multi-drop setup, there is a restriction in the use of
RTU addresses. For example, RTU addresses 32 and 42 for two
CIU 888s connected to the same RS-485 line will malfunction, while
RTU addresses 32 and 34 will work properly (see FIGURE 1-7).
FIGURE 1-7 Schematic representation of the handling of request and reply between a host system
and gauges underneath a downlink CIU in RS-485 multi-drop configuration

Honeywell CIU 888 Specifications

General

Brand	Honeywell
Model	CIU 888
Category	Recording Equipment
Language	English