5 Operation
5.11.2 External Device Monitor (EDM1)
5-86
5.11.2 External Device Monitor (EDM1)
The external device monitor (EDM1) functions to monitor failures in the HWBB function. Connect the moni-
tor to feedback signals to the safety function device.
Note: To meet the performance level d (PLd) in EN ISO13849-1, the EDM signal must be monitored by a host controller.
If the EDM signal is not monitored by a host controller, the system only qualifies for the performance level c (PLc).
Failure Detection Signal for EDM1 Signal
The relation of the EDM1, /HWBB1, and /HWBB2 signals is shown below.
Detection of failures in the EDM1 circuit can be checked using the following four status of the EDM1 signal
in the table. Failures can be detected if the failure status can be confirmed, e.g., when the power supply is
turned ON.
Signal
Name
Logic
/HWBB1 ON ON OFF OFF
/HWBB2 ON OFF ON OFF
EDM1 OFF OFF OFF ON
WARNING
• The EDM1 signal is not a safety output. Use it only for monitoring a failure.
To Next Page
Loading...
