Servo Inverter i950 FW: from V01.05.02.1788
Response of the new versionThe status bit 'PPI is valid' (0x2C65:3 Bit 0) is now correctly set to TRUE or FALSE after power-on (reboot), depending on the encoder type and the status before power-off.
What happens?
Monitoring of the polling identification 'PPI Validation monitoring' (parameter 0x2C65:x):
The status bit 'PPI is valid' (0x2C65:3 bit 0) is set to TRUE after power-on, so that the motor could be started without PLI, although only one incremental encoder is connected.
For incremental encoders, the polling information is not available after power-on, so that the PLI must be executed first. The status bit0 must therefore be set to False at first.
If an absolute encoder is used, status bit 0 is processed correctly.
When does the behaviour occur
Which products are affected?
Servo Inverter i950 FW
Short-term measures; Evaluation/Recommendations:
For synchronous motors with incremental motor feedback system, execute the polling identification (PLI) for safety reasons after each power-up, regardless of the display under 0x2C65:3 bit 0 (status bit 'PPI is valid').
Operating a synchronous motor with incorrect polling information has corresponding effects on the drive behavior. It can lead to reduced torque and, in the worst case, to the synchronous motor speeding up.
Background information:
The drive controller requires the current angular position of the rotor, the pollage, for the operation of synchronous motors (SM).
This information is only available immediately after power-on for encoder types that can represent a motor revolution absolutely. For incremental encoder types, it is first necessary to execute the poll position identification to determine the current poll position.
Encoder types for which the current polling position is available immediately after power-on:
- Hiperface SinCos absolute encoder (singleturn, multiturn)
- SSI absolute encoder
- Absolute encoder Hiperface DSL (OCT encoder)
- Resolver with pole pair number = 1 (2 poles)
- Special case: resolver with number of pole pairs = number of pole pairs of the synchronous motor
- Special case: Encoder with line count = 1
'incremental' encoder types that require the PLI to be executed after power-up:
- SinCos encoder
- TTL Encoder
- multi-pole resolvers with pole pair number >=2 (>=4 poles), except the resolver and the motor have the same pole pair number
Automatic Translation
