Nor-Cal SDC15 Controller - Manual (Page 43)

4-5
■ Connection of open collector output to digital input
■ Connection of communication (RS-485) cable
● 3-wire system
Handling Precautions
• Do not connect DA and DB. Doing so might cause damage to this
unit.
• Ground the shield line to one point on one side of the cable.
• Do not connect any terminating resistor to both ends of the
communication path. Doing so might cause the communication to
fail.
• Even though any units requiring the terminating resistor exist in the
communication path, do not connect any terminating resistor.
• Be sure to connect SG terminals each other.
Failure to do so might cause unstable communications.
Chapter 4. WIRING
This unit
16
17
18
5V
16
17
18
16
Master station
DA
DA
DB
DB
SG
SG
SG
FG
+
-
This unit (slave station)
This unit (slave station)
Shield
Shield
17
18