Synrad 32-1 - Control Signals

SYNRAD® 32-1 Operator’s Manual Version 2.2
36
User I/O Connections
Technical Reference
Control signals
Control signals
Operating modes
Much of the information provided in this section describes the use of a SYNRAD® UC-2000
Universal Laser Controller to provide tickle and PWM signals to the laser. If you are using an
alternate method of laser control, thoroughly review this section for an understanding of the
signal requirements necessary to control SYNRAD 32-1 lasers. The table below lists input volt-
age and current specications for 32-1 (PWM) inputs. Tables above and below provide specic
tickle pulse and PWM signal parameters.
Table 4-3 Input signal specications.
Parameter Specication
Logic Low (O State) 0.0 V to +0.5 VDC; 0.0 VDC nominal
Logic High (On State) +3.5 V to +10.0 VDC; +5.0 VDC nominal
Maximum Current Load 6 mA (32-1 / 32-1); 12 mA (32-1)
Tickle pulse
32-1 lasers require a 1 µs tickle pulse delivered at a nominal 5 kHz clock frequency from the
Controller. Tickle pulses pre-ionize the laser gas to just below the lasing threshold so that any
further increase in pulse width adds enough energy to the plasma to cause laser emission.
This tickle signal causes the laser to respond predictably and almost instantaneously to PWM
signals, even when there is considerable delay (laser o time) between applied PWM signals.
The lase threshold is preset for 3 µs ±0.5 µs based on a PWM and tickle frequency input of 5
kHz. See the following table for tickle specications.
Caution
Applying PWM pulses directly to the laser without rst sending
tickle pulses, for at least two seconds, will cause unpredictable la-
ser emission, degrade optical rise time, and may lead to RF Driver
failure.
Possible
Equipment
Damage