A07532 — Drive: Encoderless control not commissioned

This alarm means that encoderless operation has been selected as the fault response to encoder faults (p0491), although the encoderless control has not yet been commissioned. The note to the message adds that, in at least one drive data set (DDS), the load moment of inertia is zero (p1498 = 0). The drive executes no reaction and the message needs no acknowledgement; depending on the drive configuration, the same condition can also be signalled without a reaction (N).

• Encoderless operation is set as the fault response to encoder faults (p0491), but the encoderless control has not been commissioned yet.
• In at least one drive data set (DDS) the load moment of inertia is zero (p1498 = 0).

1. Make sure the speed controller has already been optimized for operation with encoder; the optimized P gain is then available in p1460.
2. Set the load moment of inertia in p1498, e.g. using the function module "Moment of inertia estimator/OBT" or "AST" for SINUMERIK.
3. If Safety Extended Functions with encoder in the 1-encoder system are enabled, check that p9516 is set so that no STOP A follows an encoder fault, and that the transition time from STOP F to STOP B (p9555) is long enough to brake the motor.
4. Set the current setpoint for open-loop controlled operation without encoder (p1612) for static loads, e.g. a vertical axis without weight compensation: preset value plus the torque-generating current (r0077) for the base load.
5. Set the speed controller for encoderless operation: p1470 = optimized p1460/16 for a sampling time of 125 µs, p1470 = optimized p1460/25 for 62.5 µs, p1470 = optimized p1460/30 for 31.25 µs (P gain); p1472 = 140 ms (integral time, default value); p1451 = 10 ms (speed actual value smoothing for encoderless operation).
6. Set the encoderless operation current reduction: p0642 = 2*p0318/p0640; for a result above 100%, enter 100%.
7. If the motor moment of inertia changes significantly, activate the moment of inertia estimator using the function module "Moment of inertia estimator/OBT".
8. Save the set values non-volatile (copy RAM to ROM).
9. Test the function while moving with p4642 = 1 (encoder fault test function).
10. If the result is not satisfactory, optimize the encoderless operation manually, e.g. by temporarily switching over to encoderless operation using p1300 = 20.

• p0491 — motor encoder fault response (ENCODER): setting encoderless operation here as the fault response is what raises this alarm while the encoderless control is not commissioned.
• p1498 — load mass: the load moment of inertia; enter it here, e.g. with "Moment of inertia estimator/OBT" or "AST" for SINUMERIK, because it is zero in at least one DDS.
• p1460 — velocity controller P gain: read the optimized P gain for operation with encoder here; it is the basis for p1470.
• p1470 — speed controller encoderless operation P gain: set it from p1460, divided by 16, 25 or 30 depending on the sampling time (125 µs, 62.5 µs, 31.25 µs).
• p1472 — speed controller encoderless operation integral time: set the default value 140 ms.
• p1451 — speed actual value smoothing time sensorless: set 10 ms for encoderless operation.
• p1612 — current setpoint for open-loop controlled operation without encoder: set it for static loads and add the base-load portion from r0077.
• r0077 — CO: current setpoint torque-generating: read the torque-generating base-load current here for the p1612 setting.
• p0642 — encoderless operation current reduction: set it to 2*p0318/p0640, limited to 100%.
• p0318 — motor stall current: numerator of the p0642 formula.
• p0640 — current limit: denominator of the p0642 formula.
• p4642 — encoder fault test function: set to 1 to test the encoderless switchover while moving.
• p1300 — open-loop/closed-loop control operating mode: set 20 to switch over temporarily to encoderless operation for manual optimization.
• p9516 — SI Motion encoder configuration safety functions (Control Unit): set so that no STOP A follows an encoder fault for 1-encoder Safety.
• p9555 — SI Motion transition time STOP F to STOP B (Control Unit): check that the time is long enough to brake the motor.

No acknowledgement is required — the drive executes no reaction for this message. Once the encoderless control has been commissioned as described (ending with copy RAM to ROM and the moving test with p4642 = 1), the alarm clears itself.