Sonic Alert Digital Program Controller DCP301 - Manual (Page 49)

Chapter 4. WIRING
4-17
● 5-wire system RS-485 mutual connection
57
58
59
60
61
SDA
SDB
RDA
RDB
SG
FG
57
58
59
60
61
SDA
SDB
RDA
RDB
RDA
RDB
SDA
SDB
SG
FG
SG
FG
57
58
59
60
61
SDA
SDB
RDA
RDB
SG
FG
Terminating resistor
Terminating resistor
Terminating resistor
Terminating resistor
Slave station DCP301
Shielded cable
Shielded cable
Shielded cable
Master station
Slave station DCP301
Slave station DCP301
Provide terminating resistor of 150
Ω±
5%, 1/2W min. at both ends of the communications path.
Grounding of the shielded FG terminal should be carried out at only one end and not both ends.
Be sure to connect SG terminals each
others.
Failure to do so might cause unstable
communications.
Handling Precautions