ProtEX-MAX PD8-6100 Strain Gauge, Load Cell, and mV Meter
Instruction Manual
27
Shunt Calibration
The PD8-6100 is equipped with a means of simulating
strain in a strain gauge bridge circuit, via a shunt
resistor included inside the meter. This technique is
performed by enabling the “shunt resistor” switch
(switch 5), which in turn shunts one leg of a
connected strain bridge with a 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
7
0% F.S. load in the case of a 350Ω Strain Bridge.
Figure 13. Shunt Resistor
Relay Connections
Relay connections are made to two six-terminal
connectors labeled RELAY1
– RELAY4. 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
Interlock Relay Feature
As the name implies, the interlock relay feature
reassigns one, or more, alarm/control relays for use
as interlock relay(s). Interlock contact(s) are wired to
digital input(s) and activate the interlock relay. This
feature is enabled by configuring the relay, and the
corresponding digital input(s), see
Interlock Relay (Force On) Feature
on page
In the example below, an Interlock Contact switch is
connected to a digital input, which will be used to
force on (energize) the Interlock Relay. The Interlock
Relay and the Control Relay are connected in series
with the load.
•
When the Interlock Contact is closed (safe), the
Interlock Relay energizes, allowing power to flow
to the Control Relay; the corresponding front
panel LED is on.
•
When the Interlock Contact is open, the
corresponding front panel LED flashes (locked
out), the Interlock Relay is de-energized,
preventing power from flowing to the Control
Relay and the load.
Figure 15. Interlock 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
Summary of Contents for ProtEX-MAX PD8-6100
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