Unitek Miyachi LW250 Operation, Maintenance And Service Manual page 36

Input Signal Specifications (continued)
Figure 3-4. Input Transistor Signals on Connector EXT. I/O (2)

Pin No. 33, Resonator shutter: When the COM-resonator shutter circuit is closed,
the resonator shutter opens and the laser can be oscillated. If the circuit is opened, the
resonator shutter closes and the laser may not be oscillated.

Pin 33, Main (Resonator) shutter: The main (resonator) shutter will open if the
COM - Main Shutter circuit is closed while in the external control mode.

Pin No. 34, Laser start: If the COM-Laser start circuit is closed, the laser beam is
output. Apply the closing signal for at least 40 ms. When inputting repeatedly, open
the circuit for at least 40 ms. Note: When multiple welders are used simultaneously,
use a transistor signal as the Laser Start signal. Note: You can also select Laser start
(and stop) with the software. The software selection sets Pin 30 to ground (External
Start enabled). The External I/O Laser Start signal will then accept the Laser Start
signal and start the welding cycle. WARNING: You must also supply a Laser Stop
signal because, if you do not turn off the laser at the end of the welding cycle,
adjacent personnel could be exposed to radiation.

Pin No. 35, Laser stop: The COM-Laser stop circuit is normally closed. If the COM-
Laser stop circuit is opened while the laser is oscillating repeatedly (REPEAT, PPS),
laser oscillation will stop.

Pin No. 36, Emergency stop: COM-Emergency stop circuit is normally closed. If
this circuit is opened, the high voltage circuit is opened and laser oscillation is
stopped. The cooler is also stopped. If this circuit is opened, an emergency stop is
applied, regardless of application of the EXT-ON/OFF signal.

Pins No. 37-40, Schedule 1/Schedule 2/Schedule 4/Schedule 8: The set schedule is
selected according to input of schedule 1, 2, 4 and 8. For schedule selection, refer to
the following table.
Input Signal Specifications, EXT. I/O Connector (1) (continued)
990-605 REV B: May, 1997
LW250 PULSED Nd: YAG LASER
CHAPTER 3: I/O SIGNAL INTERFACE
L25INTR2.WPG
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