S_EDM1 and S_EDM2 inputs
State-controlled signal inputs for feedback signals from contactors. These inputs are connected to the N/C contacts of the contactors. Various connection options are illustrated in the application examples.
Data type: SAFEBOOL
Initial value: SAFEFALSE
If only one feedback signal is used, this must be connected in parallel to both inputs.
Connection: Connect these inputs directly to the feedback signals (N/C contacts) of the contactors to be monitored or via additional safety-related functions/function blocks. Constant SAFETRUE or SAFEFALSE values are not permitted.
If the function block is activated (input Activate = TRUE), the possible values at this input lead to the following function block behavior:
| Value | Description |
|---|---|
| SAFETRUE | A feedback signal is present. The connected contactor has dropped out (initial state). |
| SAFEFALSE | No feedback signal is present. The connected contactor is picked up (switching state). |
Verifying the initial state
If the connected contactors are in the initial state, the feedback signal at inputs S_EDM1 and S_EDM2 must be SAFETRUE.
The initial state is verified by the function block if:
- a SAFETRUE signal is present at the S_OutControl input. If the initial state is correct, the function block relays this SAFETRUE signal to the S_EDM_Out output. If not, the function block outputs an error message and the S_EDM_Out output remains in the defined safe state (SAFEFALSE).
- a SAFEFALSE signal is present at the S_OutControl input when the function block is activated and the start-up inhibit has been removed. If, after the time set at MonitoringTime has elapsed, the feedback signals S_EDM1 and S_EDM2 do not report the initial state, the function block detects an error.
Verifying the switching behavior
Once the S_EDM_Out output switches to SAFETRUE, the feedback signal at the S_EDM1 and S_EDM2 inputs must become SAFEFALSE within the permissible response time specified at MonitoringTime. Otherwise, the function block outputs an error message (output Error = TRUE) and the S_EDM_Out output switches to the defined safe state (SAFEFALSE).
If the S_EDM_Out output switches from SAFETRUE to SAFEFALSE, the switching operation is also monitored. The feedback signal at the S_EDM1 and S_EDM2 inputs must become SAFETRUE within the permissible response time set at MonitoringTime.