Zero pulse C input

With incremental encoders, a full revolution is marked by a special marker of the zero pulse C. This pulse can be used in the terminal as follows:

The current level at the zero pulse C input is displayed via process data 0x60n0:0B "Status of Input C".

Zero pulse C input 1:

Status of input C

Zero pulse C has only a short pulse duration, depending on the rotational speed. Due to the cyclic request, it is possible that the HIGH level of the zero pulse is not transferred congruently into the process data 0x60n0:0B "Status of Input C".

Counter value reset via the zero pulse C input (Enable C reset)

The counter value can be set to the value specified in index 0x80n1:1B "Reset counter value" for every full revolution of the encoder via the zero pulse C.

Set counter value via input zero pulse C (Set counter on Latch C)

The counter value can be set to a preset value during runtime via the process data by means of the zero pulse C.

Zero pulse C input 2:

Multiple activation of "Set counter on ..."

If several commands are activated to accept the preset counter value, only the command that is set first is accepted by the terminal. All other commands are ignored but remain activated, depending on the system.

  • The counter value is set to the preset counter value at the first activated event and confirmed by the bit "Set counter done" (index 0x60n0:03).
  • The counter value specification cannot be reactivated until all activated commands for the transfer of the counter value have been deactivated. This is confirmed by setting the "Set counter done" bit (index 0x60n0:03) to FALSE.

Save counter value via the zero pulse C input (Enable latch C)

The counter value can be stored at runtime via the process data and the zero pulse in "Latch value" (index 0x60n0:12).

Zero pulse C input 3:

Multiple activation of the latch function

If several commands are activated simultaneously to save the counter value in the "Latch value" process data (index 0x60n0:12), only the command that is set first is accepted by the terminal.

  • The counter value is stored in the "Latch value" (index 0x60n0:12) at the next occurring event and confirmed with the corresponding bit.
  • All other activated events are ignored.
  • The counter value storage cannot be reactivated until all activated commands for latching the value have been deactivated. This also applies if they were activated after confirmation by the occurring event.