System calibration
Calibration is an essential operation that completes readhead set-up, with the optimum incremental
and reference mark signal settings stored in the readhead’s non-volatile memory.
Before system calibration:
uClean the scale and readhead optical window (contamination around the reference mark
may result in reference mark dephasing).
uIf re-installing restore factory defaults.
uMaximise the signal strength along full axis of travel.
NOTE: CAL routine maximum speed <100 mm/s (all Ti/TD interface models).
TD interface can be calibrated in either resolution.
Step 1 – Incremental signal calibration
uEnsure Automatic Gain Control is switched off
(CAL LED on readhead is not illuminated) before beginning calibration.
uPress and release the CAL button on the end of the interface using
a 2 mm allen key or similar tool.
WARNING! Activating the CAL switch only requires 2.5 N force.
Applying excess force may permanently damage the switch.
uThe CAL LED will now periodically single-flash to indicate that
it is in incremental signal calibration mode.
uMove the readhead along the axis, ensuring you do not pass
the selected reference mark, until the CAL LED starts
double-flashing, indicating the incremental signal is now
calibrated and the new settings are stored in the
readhead memory.
uThe system is now ready for reference mark phasing.
uFor systems without reference mark, go to ‘Calibration routine - manual exit’
uIf the system does not automatically enter the reference mark phasing stage (no double-flashing of the
CAL LED) the calibration of the incremental signals has failed. After ensuring failure is not due to overspeed
(>100 mm/s), exit the calibration routine, restore factory defaults and check the readhead installation and
system cleanliness before repeating the calibration routine.
Step 2 – Reference mark phasing
uMove the readhead back and forth over the selected reference mark until the CAL LED stops flashing
and remains off. The reference mark is now phased.
uThe system automatically exits the CAL routine and is ready for operation.
uIf the CAL LED continues double-flashing after passing the chosen reference mark many times,
it is not detecting the reference mark. Ensure that the correct readhead configuration is being used.
Readheads can either output all reference marks or only output a reference mark where
a reference selector magnet is fitted.
Calibration routine – manual exit
uTo exit the calibration routine at any stage press the CAL button. The CAL button will then stop flashing.
Restoring factory defaults
When re-installing the system, or in the case of continued calibration failure, factory defaults should be restored.
To restore factory defaults;
uSwitch system off.
uPress and hold the CAL button whilst switching the system on. The CAL LED on the readhead will flash
several times, indicating that the factory defaults have been restored.
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uRelease CAL button.
uCheck the ‘Readhead mounting/installation’ and re-calibrate the system.
NOTE: System must be re-calibrated after restoring factory defaults.
Switching Automatic Gain Control (AGC) on or off
AGC can be switched on or off via the interface.
uPress and hold the CAL button on the interface for >3 seconds to switch AGC on or off. The CAL LED on
the readhead will be illuminated when AGC is active.
NOTE: The system must be calibrated before switching AGC on.
Ti0004 to Ti20KD and TD4000 to TD0040 Interface LED diagnostics
Normal setup; signal level 110% to 135%
Optimum setup; signal level 90% to 110%
Normal set-up: signal level 70% to 90%
Acceptable set-up; signal level 50% to 70%
Poor set-up; signal may be too low for reliable operation;
signal level <50%
Poor set-up; signal level <20%; system in error
Over speed; system in error
Over signal; system in error
Reference mark detected (speed <100 mm/s only)
Status
Signal Alarm output*
Indication
Incremental
Reference mark
Purple
Blue
Green
Orange
Red
Red / blank - flashing
Blue / blank - flashing
Purple / blank - flashing
Blank flash
No
No
No
No
No
Ye s
Ye s
Ye s
No
*
Alarm output will take the form of 3-state or line driven E- signal depending on interface configuration.
Also, some configurations do not output overspeed alarm. See product nomenclature for details.
-Momentary status only, while fault condition remains.
-Alarm may result in axis position error,re-datum to continue.
T101