Limit Switch Deadband
The control logic calibrates on the Minimum Limit Switch. After a short delay any time the switch is ON the calibration value from FI4 AX1calibrateLS or FI5 AX2calibrateLS will be written to the Pv register ie. FO101 AX1pv_01_1
The limit switch inherently has dead band as the position to cause the limit switch to be ON when calibration to the position where it releases to OFF requires a few degrees of travel. This introduces a small error as the Tracking phase begins.
This procedure will correct this without any instrumentation.
Enable Calibrate X18 Calibrate
Once the Minimum Limit Switch is ON, record the raw counts
ie. X1801 AX1minLS_01_1 becomes TRUE and AX1count_01_1 = 26358
Allow to track so minimum Limit Switch goes OFF.
There should be travel without the Pv changing until the Limit Switch releases.
ie. X1801 AX1minLS_01_1 becomes FALSE and AX1count_01_1 = 27075
This can be recorded in GRIDview trends with these registers.
Overlay the Limit Switch X1801 AX1minLS_01_1 with the counts AX1count_01_1 for the exact count.
Then do this calculation:
27075 – 26358 = 717 counts
717 / 29260 (Pulses per 360.0 deg revolution ie. AX1ppr) = 0.00407
0.00407 * 360.0 = 8.82 degrees deadband enter into AX1limitSWdb or AX2limitSWdb