4-13 Connecting For Communications; Rs-485 Interface - Honeywell DCP301 User Manual

Chapter 4. WIRING

4-13 Connecting for Communications

Some controller models support the RS-485 communications interface. Select the RS-485 communications models
by selected the required catalog No.
Connect as follows.
Handling Precautions

RS-485 interface

Handling Precautions
4-16
The DCP301 operates as a slave station.
Add-on terminal base
SDA
57
SDB
58
RDA
59
RDB
60
SG
61
• Multi-drop connection of slave stations is possible.
• Make sure that different addresses are set for each slave station.
• Provide terminating resistor (total of 4 in the case of a 5-wire system connec-
tion) on both ends of the communications path. Use terminating resistor of
150 5%, 1/2W min.
• In the case of a 3-wire system connection, short-circuit terminals (57) and (59),
(58) and (60) on the DCP301.
• Do not short-circuit the RDA and RDB, or SDA and SDB terminals. Doing so
might damage the DCP301.