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3.2 Connecting components
LDC340 / Page 16
If an external monitor diode is used it must be connected via coaxial cable with the
outer conductor to pin 2 and the inner conductor to pin 4.
3.2.2 Using the interlock input
The interlock consists of two pins that have to be connected (closed) in operation.
These are pin 1 and pin 5 of the 9 pin D-SUB jack at the rear of the unit.
If the two pins are not connected (Interlock loop open) the laser cannot be switched
on.
Furthermore a red LED "INTERLOCK" on the front panel of the LDC340 will indicate
the interlock to be open.
Should the interlock open with the laser switched on there will be an acoustic signal
and the laser is switched off immediately.
It is possible to connect several switches in series to the interlock pins setting up a
closed loop that can be opened by each switch. Thus different protective functions
can be realized simultaneously via the interlock.
3.2.2.1 Examples of various protective functions
External Emergency key in the lab
An external emergency key (opener) is connected to the two pins of the interlock or
in series to other interlock switches.
Temperature control
Sometimes you may want to monitor the cooling loop of a high-power diode laser. A
suitable setup offers a switch that will open in case of an error.