Synrad Novanta OEM ti Series, User Manual

Page: 46 / 106

OPERATING MODES PAGE | 46
Operating modes
External control
In addition to controlling the laser using a UC-2000 Controller, controlling externally without a UC-2000,
is also possible. The two primary elements of laser control are gating, the ability to turn the laser on and
off at the appropriate times, and power, the ability to control the laser’s output energy. Both gating and
power can be handled by a device such as a personal computer, Programmable Logic Controller (PLC),
or function generator capable of sending PWM pulses at the proper time (gating) and with the proper
duty cycle (power).
Analog voltage or current control
Although ti-Series lasers cannot be controlled directly by analog voltage or current signals, this type of
control is possible when using the UC-2000 Controller. The Controller is connected normally to the laser
and analog voltage, or current signals sent to the UC-2000’s ANV/C connector then control both laser
gating and power.
To generate the correct analog voltage from a computer or PLC, a Digital-to-Analog (D/A or DAC) card
capable of generating 0 V (laser off) to 10 V (maximum laser power) must be installed. To generate the
proper analog current, install a D/A card that can generate 4 mA (laser off) to 20 mA (maximum power).
Software able to control your analog output card is required for either configuration.
Continuous wave (CW)
In some applications, such as high-speed marking or cutting, the time constant of the laser and the PWM
modulation causes a series of dots that may be visible on the marking surface instead of a “clean” line.
Operating the laser in CW mode will prevent this behavior from occurring. To operate the laser in CW
mode, apply a co5 VDC signal to Pin 9, PWM Input, and Pin 1, PWM Return, on the User I/O
connector. This constant voltage source forces the internal switching electronics to remain on, providing
continuous and uninterrupted laser output power. During CW operation, output power cannot be
changed. To adjust output power, refer back to the Pulse Width Modulation (PWM) section for
information regarding high frequency operation
.
Warning: Serious Personal Injury
Always use shielded cable when connecting your PWM Command signal source to the laser’s CTRL
connections.
In electrically noisy environments, long lengths of unshielded wire act like an antenna and may
generate enough voltage to trigger uncommanded lasing.