Which products are affected?
9300EP servo positioning controller as of versions V2.5 and V6.1
Function description
With nErr an additional function is made available for monitoring the speed following response. The actual speed value returned by the speed sensor is compared with the speed setpoint on the speed controller. If the difference between the two signals is outside the window selected in C0576 an nErr error is indicated in C0168 . The error response can be configured with C0579 as TRIP, message, warning, OFF or Fail-QSP. For compatibility reasons the default setting is 'OFF'.
The tolerance window in C0576 can be set in the range from 0-100 % (in relation to n-max). The default settings adjusted to 100 %, i.e. the lowest monitoring sensitivity. This monitoring function has the digital MONIT-nERR output (dig. signal source 15321). The MONIT-nErr output is set as long as deviation is outside the set tolerance window.
a) With this monitoring function the speed following response of a drive controller can be evaluated. If the system deviation at the speed controller exceeds a certain value, the drive can clearly not follow the predefined speed setpoint. In the case of the drive controller which is generally operable these can be load-end mechanical blockage or insufficient motor torque available.
Note: It may be that only the setpoint/quick stop ramps have to be adapted.
b) The monitoring function can further protect a speed sensor in speed-controlled operation so it also supplements the individual encoder monitoring functions. The effect of faults in the encoder system is that the actual speed value is not formed correctly, thus generally resulting in a larger system deviation at the speed controller than in the normal operating state. The nErr window should in practice be set to at least twice the value of the system deviation occurring in operation.
Note: If monitoring of a speed sensor is desired, the error response should definitely be set as TRIP. The setpoint/QSP ramps may have to be adapted to the application with longer times.
Applications
Speed-controlled applications:
- Applications in which a certain speed following response has to be maintained.
- Expanded monitoring capability of the speed sensor.
