Woodward MRM4, Manual

Page: 30 / 460

Installation and Connection
Digital inputs
For each digital input group the related voltage input range has to be
parametrized Wrong switching thresholds can result in
malfunctions/wrong signal transfer times.
The digital inputs are provided with different switching thresholds (can be parametrized) (two AC and five DC in-
put ranges). For the six grouped (connected to common potential) inputs and the two non-grouped inputs, the
following switching levels can be defined:
•
24V DC;
•
48V DC / 60V DC;
•
110 V AC/DC; and
•
230 V AC/DC.
If a voltage >80% of the set switching threshold is applied at the digital input, the state change is recognized
(physically “1”). If the voltage is below 40% of the set switching threshold, the device detects physically “0”.
The ground terminal has to be connected to the »-pole« when using DC
supply.
Use of the 24 V DC Output is prohibited. This output is exclusively for
factory testing and commissioning.
Page 30 EN MRM4 01/11