F07940 — Sync-line-drive: Synchronizing error

F07940 is reported by the Sync-line-drive function when synchronizing the drive to the line supply ends in an error. The manuals describe it for S120/S150 and for G130/G150, and describe the same situation from two sides: after synchronization has been completed, the phase difference (r3808) is greater than the threshold for phase synchronism (p3813); or synchronization is interrupted by an OFF1 or OFF3 response or by the enable being withdrawn (p3802 = 0); on S120/S150 additionally, the phase difference cannot be held within the time limit (p3818). On S120/S150 the fault value in r0949 tells you in binary which of these tripped; the G130/G150 manual names the conditions without bit numbers.

• Synchronizing the drive to the line supply ran into an error; the two manuals name the triggers as follows.
• After synchronization had been completed, the phase difference (r3808) exceeded the threshold for phase synchronism (p3813) — on S120/S150 for longer than 1 second, and this is the condition the G130/G150 manual names first.
• An OFF1 or OFF3 response arrived while synchronizing was still running: on S120/S150 while the motor was being synchronized to the line supply, on G130/G150 while closed-loop phase control was active (r3819.6 = 1) or synchronism had already been reached (r3819.2 = 1).
• The enable was withdrawn (p3802 = 0) while synchronizing was still in progress (S120/S150), or while closed-loop phase control was still active (G130/G150, r3819.6 = 1).
• On S120/S150 only: within the time limit (p3818) the phase difference could not be continuously limited to the threshold value.

1. Read the fault value r0949 in binary: bit 0, bit 1 or bit 2 shows which trigger applied on S120/S150. On G130/G150 compare the situations above directly.
2. If the phase difference was the trigger (bit 0 or bit 2 on S120/S150): if required increase the threshold for phase synchronism (p3813), increase the phase controller limiting (p3811), and increase the threshold for the frequency difference (p3806). For G130/G150 the manual names increasing p3813 if required as the remedy.
3. If OFF1/OFF3 or the enable interrupted synchronizing (bit 1): complete synchronizing before OFF1 or OFF3 — on S120/S150 wait for r03819.2 = 1, on G130/G150 for r03819.0 = 0 — and withdraw the enable (p3802 = 0) only once synchronism is reached (r3819.2 = 1).
4. If the time limit was exceeded (bit 2): increase the synchronization time limit (p3818).

• On S120/S150 the message value %1 is the fault value in r0949, interpreted binary:
• Bit 0 = 1: after synchronization has been completed, the phase difference (r3808) is greater than the threshold value for phase synchronism (p3813) for longer than 1 second.
• Bit 1 = 1: while synchronizing the motor to the line supply, an OFF1 or OFF3 response occurred, or the enable was withdrawn while synchronizing (p3802 = 0).
• Bit 2 = 1: within the time limit (p3818), the phase difference was not able to be continuously limited to the threshold value.
• For G130/G150 the manual prints no message value for this fault.

• r0949 — fault value; read it in binary to identify which bit this fault set.
• r3808 — CO: Sync-line-drive phase difference; shows the phase difference that is compared against the threshold in p3813.
• p3813 — Sync-line-drive phase synchronism threshold value; increase it if the phase difference stays above it.
• p3811 — Sync-line-drive frequency limiting; increasing it gives the phase controller more limiting.
• p3806 — Sync-line-drive frequency difference threshold value; increase it alongside p3813 for the phase-difference causes.
• p3818 — Sync-line-drive synchronization time limit; extend it when synchronization cannot be completed within the set time.
• p3802 — BI: Sync-line-drive enable; keep it at 1 until synchronism is reached (r3819.2 = 1).

The response is the same in both manuals: the drive coasts down (OFF2) and the fault can be acknowledged immediately before the drive will run again. Remove the cause first — for example, let synchronization complete (r3819.2 = 1) before issuing OFF1/OFF3 or withdrawing the enable (p3802 = 0) — then acknowledge the fault.