Renishaw HS20 Installation Manual page 53

Stage 1 - Pre HS20 feedback testing
Prior to system integration it is necessary to complete a number of sub-system tests. The results of
all of the following tests should be logged on the test sheets provided in Appendix C.
Laser power fail test
Switch off the 24v power to the HS20 laser in turn and confirm that the controller flags "encoder error"
on the associated axis and check that this error would cause the axis motion to be disabled.
Laser unstable test
Restore 24V power to the HS20 laser, the laser will start a preheat cycle. During this period the left
hand LED (laser status LED) on HS20 should be AMBER, the /UNSTABLE status output line will be
LOW and the digital quadrature lines will be tristated. Confirm that during preheat the controller flags
"encoder error" on the associated axis. Confirm that axis motion will be disabled by this error, and that
any additional diagnostic information presented on the controller screen is correct (e.g. "Axis X - Laser
Unstable").
Wait for the preheat cycle to finish (10-15 minutes). At this point both LEDs on the HS20 should
turn GREEN, the /UNSTABLE status output line will go HIGH and the digital quadrature lines will
become active. Confirm that the "encoder error" shown by the controller clears and that any additional
diagnostic information on the display is correctly updated.
Beam low test
Partially block the beam from the HS20 (e.g. by rotating the shutter slightly) so that the right hand LED
(signal condition LED) on HS20 goes AMBER. The /BEAM_LOW status output line will go LOW but
the digital quadrature lines will remain active. Confirm that the controller flags an "encoder warning"
on the associated axis, and that any additional diagnostic information presented on the controller
screen is correct (e.g. "Axis X - Low signal"). It is not necessary for axis motion to be disabled by /
BEAM_LOW status.
Restore full signal strength. At this point both LEDs on the HS20 should turn GREEN and the /BEAM_
LOW status output line will go high. Confirm that the "encoder warning" shown by the controller clears
and that any additional diagnostic information on the display is correctly updated.
Beam block test
Totally block the beam from the HS20 (e.g. by rotating the shutter) so that the right hand LED (signal
condition LED) on HS20 goes RED. The /BEAM_BLOCK status output line will go LOW and the digital
quadrature lines will be tristated. Confirm that the controller flags "encoder error" on the associated
axis. Confirm that axis motion will be disabled by this error, and that any additional diagnostic
information presented on the controller screen is correct (e.g. "Axis X - No signal"). Note that it's not
unusual that blocking the beam will also cause an /OVERSPEED error, so an "Axis X - Overspeed"
message may also appear (see below),
Restore full signal strength. At this point the right hand LED on the HS20 should remain RED, the /
BEAM_BLOCK status output line will remain LOW, and the digital quadrature lines will remain
tristated. (This is because BEAM_BLOCK errors are latched).
Use the appropriate controller function to send a /RESET signal to the HS20. Check that both LEDs
on HS20 turn GREEN. At this point the /BEAM_BLOCK status output line will go HIGH and the digital
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