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TONiC RESM20 Functional Safety installation guide and safety manual Original instructions
17
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
X
Clean the scale and readhead optical window (contamination around the reference mark may result in
reference mark dephasing).
X
If re-installing the readhead, restore factory defaults.
X
Maximise the signal strength along full axis of travel.
NOTE:
Calibration (CAL) routine should be carried out at slow speed (<100 mm/s or less than the
readhead maximum speed, whichever is slowest).
Step 1 – Incremental signal calibration
X
Ensure Automatic Gain Control (AGC) is switched off – C
AL
LED on readhead is not illuminated –
before beginning calibration.
X
Press and release the CAL button on the end of the interface using a 2 mm Allen key or similar tool.
NOTE:
Activating the CAL switch only requires 2.5 N force. Applying excess force may permanently
damage the switch.
Set-up LED
CAL button
Ti interface
DOP interface
X
The CAL LED will now periodically single-flash to indicate that it is in incremental signal calibration
mode.
X
Move 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.
X
The system is now ready for reference mark phasing.
X
For systems without reference mark, go to ‘Calibration routine – manual exit’.
X
If 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 or exceeding the readhead maximum speed), 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
X
Move the readhead back and forth over the reference mark until the CAL LED stops flashing and
remains off. The reference mark is now phased.
X
The system automatically exits the CAL routine and is ready for operation.
X
For the safety function to be valid, customer commissioning tests must be performed:
see ‘Commissioning test’ on page 3
.
X
If the CAL LED continues double-flashing after passing the 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.
NOTE:
The LED on the interface will flash blank when the reference mark is detected (>100 mm/s only).
It indicates the presence of a reference mark, not the phasing status.
Calibration routine – manual exit
X
To exit the calibration routine at any stage press the CAL button. The CAL LED on the readhead will
then stop flashing.
X
For the safety function to be valid, customer commissioning tests must be performed:
see ‘Commissioning test’ on page 3
.
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
X
Switch system off.
X
Press 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.
X
Release CAL button.
X
Check
‘Readhead mounting and alignment’ on page 16
, and re-calibrate the system.
NOTE:
System must be re-calibrated after restoring factory defaults.
Switching AGC on or off
AGC can be switched on or off via the interface.
X
Press 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.
CAL LED
Settings stored
Single-flashing
None, restore factory defaults and re-calibrate
Double-flashing
Incremental only
Off (auto-complete)
Incremental and reference mark