Siemens SIMATIC S7-1500 Manual page 40

Applications of the F-I/O module
5.5 Application: Connecting a load per digital output, PP switching
In order to achieve SIL3/Cat.4/PLe with this wiring, you must install a qualified actuator, for
example, in accordance with IEC 60947.
In PP operation, the actuator can no longer be shut down if a cross circuit has developed
between a positive potential (e.g. L+) and DQ. To prevent cross circuits between a positive
potential (e.g. L+) and DQ, you must route the cables used to connect the actuators in a
cross-circuit-proof manner (for example, as separate, sheathed cables or in separate cable
ducts).
In this application, you have to connect two ground terminals for safety reasons. Otherwise,
the maximum residual current at signal "0" (specified in the technical specifications) cannot
be maintained if a single ground line is interrupted.
PP operation
In the event of an error at a non-passivated, non-activated output, a brief 1-signal can occur
with a duration of 2x max. cycle time (T
Parameter assignment
Assign the following parameter for the corresponding channel group:
Table 5- 4
Parameter
Operating mode of the output
40
WARNING
WARNING
WARNING
WARNING
Parameter
) + max. readback time dark test (Trb).
cycle
PP switching
Digital output module F-DQ 8x24VDC/2A PPM (6ES7526-2BF00-0AB0)
Manual, 01/2016, A5E03858037-AA