Wiring
3-5
IM 178-4
C79000-G7076-C178-01
D
igital Inputs I0 to I2
Per channel, the IM 178-4 has three digital inputs. These are operated with a rated
voltage of 24 V.
The digital inputs are electrically isolated from the DP interface and the sensor
signals.
The digital inputs I0 and I1 have fixed functions depending on the parameter
assignment (see Chapter 6). Pin I0 must be connected using a shielded cable.
D
igital Outputs Q0 to Q2
Per channel, the IM 178-4 has three digital outputs. These are supplied from the
24 V power supply 2L+.
The digital outputs are electrically isolated from the DP interface and the sensor
signals.
The digital outputs are current–sourcing switches and can accept a load current of
0.5 A. They are protected against overload and short–circuits.
Note
The direct connection of relays and contactors is possible without external
protective circuits.
Analog Outputs
Per channel, the IM 178-4 has one analog output of
±
10 V with a resolution of
±
13
bits.
The analog outputs must be connected using shielded cables.
Note
Turning on the auxiliary voltage 1L+ can lead to the analog outputs supplying a
spurious pulse for several ms. This spurious pulse must not cause the power
circuits to be activated. This must be avoided by appropriate external wiring of the
module (digital output to enable the power circuits).
