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:
- Counter value reset: the counter value is reset to the value set in index 0x8001:1B "Reset counter value" (default setting: "0") (Enable C reset)
- Set counter value: the counter value is set to a predefined value (Set counter on Latch C)
- Save counter value: the counter value is saved in the latch register (Enable latch C)
The current level at the zero pulse C input is displayed via process data 0x60n0:0B "Status of Input C".
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 0x8001:1B "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.
- Counter value setting via index 0x70n0:11 "Set counter value"
- Activation of the counter value setting via zero pulse C:
- Index 0x70n0:08 "Set counter on latch C" = TRUE
With the next zero pulse the counter value is set to the counter value specified in index 0x70n0:11 (Set counter value). - For confirmation the "Set counter done" bit in index 0x60n0:03 is set to TRUE.
- The counter value setting via the zero pulse C cannot be reactivated until the "Set counter on latch C" bit in index 0x70n0:08 is set to FALSE.
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.
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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).
- The function is activated by setting the bit in "Enable latch C" (index 0x70n0:01) to TRUE.
- The current counter value is saved in "Latch value" (Index 0x60n0:12) with the next zero pulse at input C. The subsequent pulses have no influence on the latch value.
- The "Latch C valid" bit (Index 0x60n0:01) is set to TRUE.
- After reactivating "Enable Latch C" (index 0x70n0:01) a new counter value cannot be written to the Latch input until the values of the "Enable Latch C" bit (index 0x70n0:01) and the "Latch C valid" bit (index 0x60n0:01) are FALSE.
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.
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