A07498 — LR: Measuring probe evaluation not possible

A07498 is raised as “LR: Measuring probe evaluation not possible”: while the drive was evaluating the measuring probe, an error occurred, so the evaluation result cannot be used. Which of four errors the drive found is stored as the alarm value in r2124. Depending on how the drive is configured, the same condition can also be issued as fault F07498; in that case the drive switches off with OFF1 and must be acknowledged immediately before it will run again.

• An error occurred while the drive was evaluating the measuring probe, so the evaluation has failed. The alarm value in r2124 (read it as a decimal number) tells you which situation the drive encountered — the values are decoded in the fault value list below. The manuals for the G130/G150 and the S120/S150 describe this cause identically.

1. Read the alarm value from r2124 as a decimal number; it points to the specific error and the matching step below.
2. If you do not need the measuring probe function at all, switch the evaluation off by setting the BI p2509 to signal 0.
3. Alarm value 6: the input terminal for the measuring probe has not been set — set it via p0488/p0489 or via p2517/p2518.
4. Alarm value 4098: an error occurred during initialization of the measuring probe — check the Control Unit hardware.
5. Alarm value 4100: the measuring pulse frequency is too high — reduce the frequency of the measuring pulses at the measuring probe.
6. Alarm value above 50000: the measuring clock cycle is not an integer multiple of the position controller clock cycle — change the clock cycle ratio to an integer multiple. Tmeas [125 µs] = alarm value - 50000 gives the currently effective measuring clock cycle from the alarm value. With PROFIBUS the measuring clock cycle corresponds to the PROFIBUS clock cycle, which you can read in r2064[1]; without PROFIBUS it is an internal cycle time that cannot be influenced.

The message value contains the alarm value; the drive also stores it in r2124. Interpret it as a decimal number:

• 6 — the input terminal for the measuring probe is not set.
• 4098 — an error occurred while the measuring probe was being initialized.
• 4100 — the measuring pulse frequency is too high.
• above 50000 — the measuring 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 identify which of the four probe errors occurred.
• p2509 — BI that activates the measuring probe evaluation; set it to signal 0 to switch the evaluation off and clear the message when you do not need the function.
• p0488 — input terminal of measuring probe 1; where you set the missing terminal when the alarm value is 6.
• p0489 — input terminal of measuring probe 2; the matching place to set the terminal for the second probe.
• p2517 — BI for direct measuring probe 1; the alternative place to assign the probe 1 input for alarm value 6.
• p2518 — BI for direct measuring probe 2; likewise for the second probe.
• r2064[1] — shows the PROFIBUS clock cycle; with PROFIBUS the measuring clock cycle corresponds to it, so compare it here when the alarm value is above 50000.

Once the cause has been corrected, the alarm clears itself; A07498 as an alarm needs no acknowledgement. If the drive is configured to issue the same condition as fault F07498 instead, the drive switches off with OFF1 and you must acknowledge the fault immediately before it can be restarted.