Honeywell DCP552 Mark II User Manual page 43

3-wire system RS-485 connection diagram
Terminating resistor
Master station
RDA
RDB
*
SDA
SDB
SG
FG
Terminating resistor
Attach 1/2W or greater terminating resistances of 150Ω ±5% at each end of the
communications lines. Ground the shield FGs at one end in one location, not at
both ends.
When only three RS-485 terminals are provided, the areas designated with an
asterisk (*) are connected internally.
*
Shield
Shield
Slave station side DCP552
SDA
60
SDB
61
RDA
62
RDB
63
SG
64
FG
Shield
Slave station side DCP552
SDA
60
SDB
61
RDA
62
RDB
63
SG
64
FG
Slave station side DCP552
SDA
60
SDB
61
RDA
62
RDB
63
SG
64
FG
Chapter 4. WIRING
4-15