
B-70315EN/02 APPENDIX F.CONTROL SEQUENCES IN LASER OSCILLATOR
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[SQ16, 17, 18] Setting the laser start switch to ON starts evacuation, which continues
until the pressure designated by PRM No. 15240 is reached. After
evacuation up to the value set in PRM No. 15240, gas pressure control
starts. Then, the pressure increases to the value set in PRM No. 15241.
When 45 seconds has elapsed after gas pressure control starts, a check
is made to see if the intra-tube gas pressure is within ±20 relative to
the value of PRM No. 15241. If the intra-tube gas pressure is not
within this range, an alarm is issued. If there is no problem, the turbo
blower starts and reaches the specified speed in about 70 seconds.
Then, the discharge preparation completion state (LRDY = 1) is set. If
the frequency reached signal is not issued by the inverter within 120
seconds of the turbo blower being started, an alarm is issued.
[SQ20] In the discharge preparation completion state (LRDY=1), the
discharge start switch (HVON) is enabled.
[SQ26, 27, 28] When the discharge start switch (HVON) is turned on in the discharge
preparation completion state, a high voltage is applied to the discharge
tube to set the base discharge state. At the same time, gas pressure
control is exercised. The intra-tube gas pressure increases from the
value of PRM No. 15241 to the value set in PRM No. 15242 or 15243.
At this time, a check is made to see if the intra-tube gas pressure is
within ±50 relative to the value of PRM No. 15242 or 15243. If the
intra-tube gas pressure is not within this range, an alarm is issued. If
there is no problem, an output compensation coefficient calculation is
made.
[SQ30] This is oscillation preparation completion state (LSTR=1) in which
laser oscillation is ready.
[SQ23] When HVON is turned off, discharge ends, and the state changes from
the oscillation preparation completion state (LSTR) to the discharge
preparation completion state (LRDY). At this time, the intra-tube gas
pressure changes from the value set in PRM No. 15242 or 15243 to
the value set in PRM No. 15241.
[SQ14, 49, 12] When the oscillator start switch is set to OFF in the SQ20 state, gas
pressure control ends, and the termination of the turbo blower
operation is awaited for 70 seconds. Then, if evacuation is enabled
(when bit 2 of PRM No. 15003 is set to 1), evacuation is performed
for the period of time set in PRM No. 15256. Then, laser gas is filled
until the intra-tube gas pressure becomes equal to the atmospheric
pressure. Upon completion of laser gas filling, the purge state is set.
When the purge state is set, power OFF interlock is released, and the
power can be turned off.