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.