General information on commissioning the EL407x

The terminals support EtherCAT cycle times of up to 50 µs, but the following minimum cycle times are recommended for precise value output:
- EL4072: >= 150 µs
- EL4074: >= 250 µs
- EL4078: >= 500 µs

If these values are not reached, it cannot be guaranteed that analog value output will begin in the corresponding output cycle. This may result in delayed output in the order of several cycles. The fact that the internal analog value output can no longer follow the cycle reliably can be recognized by the incrementing of the local “SM Output” error counter CoE 0x1C32:0C.

Example EL4078:

General information on commissioning the EL407x 2:Fig.147: EL4078 with 500 µs EtherCAT cycle time, output jitter according to theory ±0.5 cycles
General information on commissioning the EL407x 3:Fig.148: EL4078 with 100 µs EtherCAT cycle time, output jitter > 1 ms

If such time-precise analog value output is required, switch to the EL41xx or EL47xx series.