Modbus rtu serial communications, Relay connections, Relay4 relay3 – Precision Digital PD6310 User Manual
Page 28: Relay2 relay1, Figure 18: relay connections
Model PD6210 & PD6310 Batch Controllers
Instruction Manual
28
Modbus RTU Serial Communications
Serial communications connection is made to an RJ45 connector labeled
M-LINK on Figure 7. Use the PDA1232 for RS-232 interfacing, the
PDA1485 for RS-485 interfacing, or the PDA8008 for USB interfacing. The
same port is used for interfacing with all expansion modules (e.g. external
relays, digital I/O).
Use the PDA1200 controller copy cable for meter-to-meter interfacing for
cloning purposes (i.e. copying settings from one controller to other
controllers).
Relay Connections
Relay connections are made to two six-terminal connectors labeled
RELAY1 – RELAY4 on Figure 7. Each relay’s C terminal is common
only to the normally open (NO) and normally closed (NC) contacts of the
corresponding relay. The relays’ C terminals should not be confused with
the COM (common) terminal of the INPUT SIGNAL connector.
C
NO
NO
NC
NC
C
RELAY4
RELAY3
4
3
6
5
2
1
C
NO
NO
NC
NC
C
RELAY2
RELAY1
4
3
6
5
2
1
Figure 18: Relay Connections