DDS EX
Explosion-Proof Transmitter and Controller Instruction Manual
21
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 trigger the interlock relay. This feature
is enabled by configuring the relay and relative digital input(s). In one example, dry interlock contacts are
connected in series to one digital input which will be used to force on (energize) the assigned interlock
power relay when all interlock contacts are closed (safe). The interlock relay front panel LED flashes when
locked out. The interlock relay would be wired in-series with the load (N/O contact). See below.
Figure 14. Interlock Connections
Analog Input Signal Connections
Analog input signal connections are made to a nine-terminal connector labeled SIGNAL on the back of the
scanner. The COM (common) terminals are the return for the 4-20 mA and the
±
10 V input signals. The
two COM terminals connect to the same common return, and are not isolated.
Current and Voltage Connections
The following figures show examples of current and voltage connections. There are no switches or jumpers
to set up for current and voltage inputs. Setup and programming is performed through the front panel buttons.
Figure 15. Transmitters Powered by Internal Supply
Figure 16. Transmitter Powered by Ext. Supply or Self-Powered
