Synrad Novanta OEM ti Series, User Manual

Page: 44 / 106

CONTROL SIGNALS PAGE | 44
Command signal
The modulated Command signal applied between Pin 9, PWM Input, and Pin 1, PWM Return, of the User
I/O connector on the ti-Series laser has three basic parameters: signal amplitude, base frequency, and
PWM duty cycle. By changing these parameters, you can command the beam to perform a variety of
marking, cutting, welding, or drilling operations.
The first Command signal parameter, signal amplitude, is either logic low—corresponding to laser beam
off, or logic high—corresponding to beam on. The laser off voltage, typically 0 V, can range from 0.0 V
to +0.8 VDC while the laser on voltage, typically 5 V, can range from +3.5 V to +6.7 VDC.
Base frequency, the second parameter, is the repetition rate of the PWM input signal. The standard base
frequency is 5 kHz, which has a period of 200 μ s. Maximum PWM frequency is 160 kHz.
The third Command signal parameter, PWM duty cycle, is the percentage of the period that the
Command signal is high. If the Command signal’s amplitude (at 5 kHz) is high for 100 μ s and low for 100
μ s, it has a 50% duty cycle; if the amplitude is high for 190 μ s and low for 10 μ s, it has a 95% duty cycle.
The following figure illustrates PWM Command signal parameters while the following table lists PWM
signal specifications.
Your user I/O PWM input consists of a high-speed optoisolator LED with a forward voltage drop (Vf) of
1.5 VDC. The PWM input frequency can range from DC (0 Hz) to 160 kHz. the following table provides
minimum, maximum, and nominal PWM signal specifications.
Table 4-3 PWM command signal specifications.
Warning: Serious Personal Injury
Because of phase differences, external tickle pulses may combine with the internally generated tickle
signal causing the LASE LED to flicker during the transition from tickle to lasing. Laser output may
occur if the LASE LED flickers.