A07578 — Encoder 2: Measuring probe evaluation not possible

A07578 tells you that the drive could not evaluate the measuring probe connected at Encoder 2: an error occurred while the probe signal was being evaluated. Which error this is is reported in the alarm value, which the drive stores in r2124 — read it as a decimal number. Depending on how the drive is configured, the same condition can also appear as the fault F07578 instead of the alarm.

• The drive detected an error while evaluating the measuring probe signal at Encoder 2.
• The manual names four possible errors behind this message; which one applies is shown by the alarm value in r2124 (see the decoding below).

1. Read the alarm value in r2124 as a decimal number; it tells you which of the four errors occurred.
2. Alarm value 6: set the input terminal for the measuring probe — either in p0488 or p0489, or in the LR direct measuring probe inputs p2517 or p2518.
3. Alarm value 4098: check the Control Unit hardware.
4. Alarm value 4100: reduce the frequency at which the probe delivers its measuring pulses.
5. Alarm value 4200: adjust the ratio so that the PROFIBUS clock cycle is an integer multiple of the position controller clock cycle.
6. If the application does not need the probe, deactivate the measuring probe evaluation by applying signal 0 to p2509 — the message then goes away.

• 6 — no input terminal has been set for the measuring probe.
• 4098 — initializing the measuring probe ended in an error.
• 4100 — the frequency of the measuring pulses is too high.
• 4200 — the PROFIBUS clock cycle is not an integer multiple of the position controller clock cycle.

• r2124 — holds the alarm value of this message; read it as a decimal number to pick the matching step.
• p2509 — BI input that activates the measuring probe evaluation; signal 0 here switches the evaluation off.
• p0488 — input terminal of measuring probe 1; used to assign the terminal when the alarm value is 6.
• p0489 — input terminal of measuring probe 2; same use as p0488 for the second probe.
• p2517 — LR direct measuring probe 1; alternative input to assign when the alarm value is 6.
• p2518 — LR direct measuring probe 2; second LR direct probe input for the same purpose.

As an alarm, A07578 does not trip the drive and needs no acknowledgment; it clears itself once the cause is removed and the probe evaluation runs again. Only when the drive is set up to output the condition as fault F07578 does it respond with OFF1, and that fault must be acknowledged immediately before the drive restarts.