Interpretation of the process data (PDO)
The process data of the terminal can be assigned to four areas (device information, channel information, use as digital input, use as digital output):
Device information | WcState | "0": proper operation |
"1" : the terminal has not exchanged any process data in this cycle | ||
InputToggle | Changes cyclically 0/1/0/1...: | |
Changes acyclically 0/1/1/0/... : | ||
State | Bit 3 =TRUE: "0": proper operation | |
AdsAddr | AMS NetId and port number of the terminal, important for acyclic communication from the controller with the CoE and registers. | |
DcOutputShift | offset of the output terminals set by TwinCAT in [ns] to the current task tick. | |
DcInputShift | offset of the input terminals set by TwinCAT in [ns] to the current task tick. |
Channel information, each for channel 1 and 2 | Ch CycleCount | Byte | iterating per cycle [0..255], can be used on the controller side to check that the terminal supplies new data in each EtherCAT cycle, expected value is therefore +1 |
Ch Out CycleCount error | Bool | Feedback channel of the corresponding output. "0": no transmission error "1": Output channel has detected count > +1 | |
Powerfail |
| "0": proper operation "1": internal error, contact Service | |
Warning |
| "0": proper operation "1": internal warning, possibly overheating | |
TxPDO |
| "0": proper operation "1": the EtherCAT data exchange with the channel has failed in this cycle | |
Input cycle Counter |
| iterating per cycle 0→1→2→3→0...: proper operation | |
| not '+1'-iterating, e.g. 0→2→2→3→0…: |
Use as digital input The process data are structured channel-oriented for control-side linking with a specific FB, therefore the DC timestamp is offered twice | StartTimeNextLatch | 64-bit DC timestamp [ns] of the first sample of the next oversampling package |
CycleCount | counts cyclically +1: | |
cyclic change +0 or +2: | ||
Input[n] | Bytewise input process data for control; |
Use as digital output The process data are structured channel-oriented for control-side linking with a specific FB, therefore the DC timestamp is offered twice | StartTimeNextOutput | 64-bit DC timestamp [ns] of the first sample of the next oversampling package |
CycleCount | 8-bit counter that can be used cyclically by the controller with +1. In case of operation, both channel counters must be used! | |
CycleCount Activate | activates the monitoring on '+1' of the CycleCount in the terminal. | |
Output[n] | Byte-wise output process data from the controller; the process data size depends on the set oversampling |