Siemens SIMATIC ET 200AL, System Manual

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Applications of the F-I/O module
5.2 Digital output applications
Digital I/O module F-DI 4+F-DQ 2x24VDC/2A, 4xM12 (6ES7146-5FF00-0BA0)
Equipment Manual, V1.0, 05/2021, A5E51082342-AA
51
Figure 5-12 F-DI application mode 8: External sensor supply (1oo2 evaluation of two single channel sensors with
nonequivalent outputs shown)
Parameter assignment
Parameter name Parameter value
Sensor evaluation 1oo2 evaluation, 2 channel - 4 wire nonequivalent
Sensor supply External
5.2 Digital output applications
You should consider the application modes presented here along with the features of the
F-DI 4/F-DQ 2 Fail-Safe module as described in the overview. Refer to "Fail-safe digital outputs
(Page 15)".
The main features of the F-DI 4/F-DQ 2 Fail-Safe module digital outputs include the following
items, which apply to each output channel:
•
The fail-safe module separately controls current flow in the P output and M output.
• The voltage at the P and M outputs is read back to confirm proper state.
• The P and M outputs are regularly tested with short ON and OFF pulses to confirm control.