Honeywell DCP551 Mark ΙΙ User Manual page 45

Chapter 4. WIRING
5-wire system RS-485 connection diagram
HANDLING PRECAUTIONS
4-14
Attach 1/2W or greater terminating resistances of 150Ω ±5% at each end of the commu-
nications lines. Ground the shield FGs at one end in one location, not at both ends.
Terminating resistor
Terminating resistor
Shield
Master station
RDA
RDB
SDA
SDB
SG
FG
Shield
Shield
Terminating resistor
Terminating resistor
• Be sure to connect SG terminals each other. Failure to do so might cause
unstable communications.
,+2##
Slave station side
SDA
60
SDB
61
RDA
62
RDB
63
SG
64
FG
,+2##
Slave station side
SDA
60
SDB
61
RDA
62
RDB
63
SG
64
FG
,+2##
Slave station side
SDA
60
SDB
61
RDA
62
RDB
63
SG
64
FG