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Interpolator Card Troubleshooting

Reading the configuration

 

1. The configuration page will initially display the settings read from the Interpolator.

2. Clicking on 'Initialize from ini' button will read in the configuration from the .ini file BUT will not write it to the interpolator.

3. Clicking alternatively between 'Initialize from ini' and 'Initialize from device' can show if there is a difference between the two.

4. If the interpolator settings are blank, the software will apply the defaults, send the configuration to the interpolator and save them to the .ini file.

Debug function - Status Latch

Clicking on the 'Status Latch' tab shows the errors latched for all three axes.

status latch tab

Any of the errors shown will cause the UCC to report a readhead error. This tab allows the error to be identified. The latest latched errors can be viewed by clicking the 'Update' button.

ErrorCause
 VrefSignal reference < 1.25V (2.1Vpp  only)
 Over speedPhase and quadrature signals are coming in too fast or too noisy to output digital signals at the set maximum output rate.
 QuadrantPhase and quadrature signals are coming in too fast or too noisy to accurately interpolate.
 Amplitude high

Phase and quadrature signals are coming in too large or too noisy to accurately interpolate.

 AmplitudePhase and quadrature signals are coming in too small or too noisy to accurately interpolate.  This threshold can be set in Advanced settings.
 Diameter The calculated diameter of the Lissajous is too small to accurately interpolate. This threshold can be set in Advanced settings.
 Signal found The Interpolator hasn’t found two complete Lissajous signals and will not calculate diameter and centre of the signals.  The CMM may not have moved since power up.
 5V Good Incorrect Voltage present on PCB.
 Ram CRC On board look up tables corrupted.  Unit will need the firmware re-flashed by Renishaw personnel.
 Config CRC No valid interpolator configuration set.

Debug function – Lissajous

Clicking on the ‘Lissajous’ tab allows the readhead signal to be viewed graphically as well displaying the latched errors and the current Reference Mark and limit switch status.

debug function

Select the axis to view using the 'Plot Options' in the bottom right corner. 

The axis signals will be shown on the main graph and should form a circular Lissajous figure as the CMM moves. The blue circle indicates the ideal signal.

A green data point on the Lissajous figure indicates the signal is OK.  Any errors detected will turn the Lissajous data point red.  When the readhead passes over a reference mark, the Lissajous data point will turn white.

The phase and quadrature signals can also be plotted against time. Select the 'Data A' or 'Data B' option.

The bar graph on the right indicates the signal strength compared to the ideal value (100%).

Any errors in the data points are latched in the ‘Latched Sample Data Errors’ box and updated by clicking on ‘Reset LEDs’.

The Interpolator PCB LED lights blue when an over speed error is detected.  This error is latched within the interpolator so that it can be easily diagnosed without a site visit.  The latched error is cleared by clicking on the ‘Clear Overspeed’ button.

The Lissajous figure can indicate the start/stop points of the reference mark to allow optimum adjustment.  Select this option by clicking on ‘Trigger On Reference’.  This may require the CMM to be repeatedly run over the reference mark to build up the data points

Ideal Reference Mark Lissajous

Using the reference mark trace on the lissajous, the reference mark pick up magnet can be physically adjusted so that the beginning and end points (A and B) are opposite the 45 degress (dotted line) of the lissajous as shown.