BECKHOFF EL6900-FB - Manual (Page 27)

Function blocks
Function blocks for TwinSAFE logic terminals 25
3.3 The OPMODE function block
3.3.1 Functional description
Operating mode selectors can be realized with the FB OPMODE. The function block has 8 inputs and 8
outputs, which are looped through one-to-one, whereby up to 8 different operating modes can be
selected. The FB OPMODE sets the corresponding output, only when an input is precisely set ("1"),
whereby the other outputs remain in a safe (“0”) state. All outputs are in a safe state if there is none or
more than one input is set. The output safe state can only be exited during start and change of operating
modes using a 0->1->0 signal sequence on the restart input, once the restart input is activated. In
addition a discrepancy time can be given, with which the change of operating mode can be monitored.
Figure 3-5: Function block OPMODE
Note
Number of inputs
At least two inputs of FB OPMODE must be connected.