Specifications

Interfacing Diamond Lasers to Systems
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on the Performance power supply). Interlock signals are accessed
through the DB9 plug marked User on Basic lasers and Interlock on
Performance lasers.
The DDI provides many more inputs and outputs than the OEM
interface. In addition to the enable and modulation signals, inputs
are provided for shutter control, the aiming laser, turning the DC
power supply on, clearing faults and selecting output signals. The
inputs are optically isolated and are to be driven by devices such as
an MC74HCT240A.
The DDI’s outputs, with the exception of shutter position and an
alert signal, are multiplexed through four lines. When an alert signal
is received, the system control must interrogate the DDI by cycling
the A and B inputs while monitoring Out 0 through Out 3 to deter-
mine the exact fault (See table titled “Diamond Digital Interface
Multiplexer” in the Diamond Operator’s Manual).
The User or Interlock connector is meant to be used for safety inter-
locks. The system interlock string, including key switches, connects
pins 8 and 9. Any break in this string shuts the laser down, so it is
not a good idea to put work chamber door switches on it. These
should be interlocked to the laser shutter (or to RF enable for
systems with manual shutters) instead.
When the DC power supply is on, Pins 1 and 2 are switched together
by a relay in the DDI. This can be used as a signal for “Laser On”
warning lights. Note that the relay contacts can only take 0.2 A at
25 V, so it is not appropriate to directly connect lights to this line.
Remote Control
Interface
The main reason for controlling a Diamond laser through the
Remote Control is that the pulse period and duration may be set on
the remote’s thumbwheel switches. This allows system controllers
without pulse outputs to be used. The remote also displays faults and
warnings, allows for their reset, and minimizes interface require-
ments. It is, in general, an inefficient way to set up a permanent inter-
face but is useful for temporary setups.
Inputs to the remote may be made through BNC connectors or
through the Interlock + Control connector J11. Tables titled “Remote
Control Unit Controls and Indicators” in the Operator’s Manual
indicate how the remote may be set up for external control.
Interlocks
External interlocks must often be connected to the Diamond laser.
These include safety interlocks such as door signals, process inter-
locks such as assist gas flow sensors and mechanical interlocks such