ABB AC500-S Safety User Manual page 386

Configuration and programming
AC500-S Libraries > SafetyBlocks_PLCopen_AC500_v22.lib
External device monitoring – The FB controls a safety output and monitors controlled actuators, e.g. subse-
quent contactors
The SF_EDM FB controls a safety output and monitors controlled actuators.
This function block monitors the initial state of the actuators via the feedback signals (S_EDM1 and
S_EDM2) before the actuators are enabled by the FB.
The function block monitors the switching state of the actuators (MonitoringTime) after the actuators have
been enabled by the FB.
Two single feedback signals must be used for an exact diagnosis of the connected actuators. A common
feedback signal from the two connected actuators must be used for a restricted yet simple diagnostic func-
tion of the connected actuators. When doing so, the user must connect this common signal to both param-
eter S_EDM1 and parameter S_EDM2. S_EDM1 and S_EDM2 are then controlled by the same signal.
The switching devices used in the safety function should be selected from the category specified in the risk
analysis (EN 954-1).
Optional startup inhibits:
Startup inhibit in the event of block activation.
n
The S_StartReset input shall only be activated if it is ensured that no hazardous situation can occur when
the PES is started.
386 AC500-S 30.03.2017