V90 EPOS uses absolute value encoder. Summary of common problems of position loss after power failure
1. overview
The basic positioning function of V90 is often used by engineers. The absolute encoder can be used to maintain the position of the device after power failure. When using the built-in basic positioning function (EPOS) of V90 PN, engineers often hear that the actual position of the axle can not be maintained after power failure. This paper provides some ideas for checking problems for your reference.
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2. V90 uses absolute value encoder. Summary of common problems of position loss after power failure
2.1 Zero Loss of Absolute Encoder after Power Failure
A. Encoder failure/damage.
B. The absolute encoder has not been operated through the "Save parameters to ROM" option of the V-ASSISTANT tool menu after returning to zero (correction).
C. Please check whether the motor of single-loop absolute encoder moves more than half-cycle and multi-loop absolute encoder moves more than 2048 cycles after power failure.
2.2 Why does the absolute encoder still lose its potential when the power is cut off and the up-voltage position is returned to zero through FB284?
FB284 function block does not support zero-return (calibration) of absolute encoder. It needs V-ASSISTANT debugging software or non-periodic communication to modify p2507 to achieve zero-return of absolute encoder. Detailed description can be referred to official documents.
2.3 When V90 is set back to the origin using FB284, AxisRef has no output.
Zero return is unsuccessful. Check Zero return operation and settings. The executeMode parameter needs to be kept high during the zero-back process.
2.4 How to Expand the Measurement Range of Absolute Encoder in EPOS Mode
Absolute encoder can expand the measurement range of absolute encoder by setting virtual multi-loops:
P29243 = 1 activates the position tracking function. P29244 sets the number of virtual multi-loops, and single-loop encoder activates the virtual multi-loops. The maximum number of loops can be set to 2048. Its effective range of movement is (+1024) loops centered on the zero position.
