F31804 — Encoder 1: Checksum error

F31804 is raised when the drive reads out the program memory on the Sensor Module of Encoder 1 and finds a checksum error. The S120/S150 manual titles the code Encoder 1: Sensor Module checksum error, the G130/G150 manual Encoder 1: Checksum error; the cause and the remedy are described identically in both. The fault value tells you which memory area is involved and by how much the checksum read out differs from the checksum at POWER ON. Depending on the drive's configuration, the same condition can also be signalled as an alarm (A) or without any reaction (N).

• A checksum error occurred while the program memory on the Sensor Module of Encoder 1 was being read out. Both manuals give only this one cause; the entries for the different drive objects do not differ.

1. Carry out a POWER ON — switch the converter off and on again.
2. Upgrade the firmware to a later version (>= V2.6 HF3, >= V4.3 SP2, >= V4.4).
3. Check whether the permissible ambient temperature for the component is maintained.
4. Replace the Sensor Module.

• The drive stores the fault value in r0949; interpret it hexadecimal.
• The value has the form yyyyxxxx hex: yyyy — memory area involved; xxxx — difference between the checksum at POWER ON and the actual checksum.

• r0949 — holds the fault value of this code; read it as a hexadecimal yyyyxxxx word to identify the memory area involved and the checksum difference.
• p0491 — Motor encoder fault response ENCODER; the manual names this parameter as a cross-reference when describing the fault.

Acknowledgment is by POWER ON: switch the converter off and on again. This is at the same time the first step of the remedy, so after restarting check whether F31804 reappears before moving on to the firmware upgrade, the ambient-temperature check and, as the last step, replacing the Sensor Module. When the drive signals the condition as an alarm (A) or without reaction (N), no acknowledgment is required.