Precision Digital PD6100 - Manual (Page 24)

Model PD6100 Strain Gauge/Load Cell Meter Instruction Manual
24
predetermined resistive load(60.4k). This technique can be used as a
means of verifying instrumentation by simulating a physical
input. With no load connected, the enabling of the shunt resistor
(switch 5) will simulate approximately a 70% F.S. load in the case of a
350Ω Strain Bridge.
Figure 13. Shunt Resistor
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 PDA8008 for USB interfacing, or the PDA1485 for RS-485
interfacing. The same port is used for interfacing with all expansion
modules (e.g. external relays, digital I/O).
Use the PDA1200 meter copy cable for meter-to-meter interfacing for
cloning purposes (i.e. copying settings from one meter to other meters).
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.
Figure 14. Relay Connections
EX+
EX-
SG- SG+
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