Siemens SIMATIC PCS 7 - Redundant Actuators and Sensors

Reaction to a channel fault
You can define the passivation characteristics, for example how redundant input/output
modules react to a channel fault (such as broken wire, short-circuit on the signal line). The
reaction to a channel fault depends on the following aspects:
● Module employed
● Configuration
● Version of the PCS 7 library
– As of PCS 7 V7.1, the potential passivation reaction is automatically detected based on
the configured modules. The passivation reaction is set channel-by-channel.
– Only the module-based passivation reaction can be selected with the Redlib V3.x library.
– You can set the channel-based passivation reaction with the Redlib library as of V4.
You will find information on the passivation reaction for individual modules in the
documentation
PCS 7 - Released Modules .
Additional information
● Section "How to configure redundant input/output modules (PROFIBUS DP) (Page 136)"
● Section "Failure of redundant I/O modules (Page 199)"
● Section "How to set the CPU for the reaction of the input/output modules to channel faults
(Page 113)"
● Manual Automation System S7-400H; High Availability Systems
● Online help for STEP 7
4.1.3.3 Redundant actuators and sensors
Detecting failures
Actuators and sensors of I/O field level can be configured redundantly for PCS 7. A requirement
therefore is, that you can configure a pair of actuators/sensors to a pair of I/O-modules. The
failure of an actuator or sensor can be detected and reported as an error in the process control
system based on the used input/output module to which the redundant actuators or sensors
are connected. If an actuator/sensor fails, the automation system continues working with the
intact actuator/sensor. This means the current status of process values can be read or output
at any time.
Note
Read the product description of the I/O module used to find out whether the module can detect
and report a failure of the connected actuators and sensors.
High availability solutions in PCS 7
4.1 Solutions for the I/O
High Availability Process Control Systems (V9.0)
48 Function Manual, 05/2017, A5E39221836-AA