Chapter 6 Making The Safety Interlock Connection - THORLABS S1FC635PM User Manual

Fiber-Coupled Laser Source
Making the Safety Interlock Connection
Chapter 6
The S1 series laser sources are equipped with a remote interlock connector located on the rear panel, see Figure
2. All units have this feature regardless of their FDA and IEC classifications. In order to enable the laser source, a
short circuit must be applied across the terminals of the Remote Interlock connector. In practice this connection is
made available to allow the user to connect a remote actuated switch to the connector (i.e. an open door
indicator). The switch (which must be normally open) has to be closed in order for the unit to be enabled. Once
the switch is in an open state the laser source will automatically shutdown. If the switch returns to a closed
condition the laser source must be re-enabled at the unit by pressing the ENABLE switch.
All units shipped from Thorlabs are configured with a shorting device installed in the Interlock connector. If you
are not going to use this feature then you can leave the shorting device installed and the unit will operate normally
as described in the procedures above.
If you wish to make use of the Interlock feature you will need to acquire the appropriate connector mate and wire
it your remote interlock switch. Next, remove the shorting device by pulling it out with a pair of needle nose pliers
and install the connector into the interlock input.
The interlock input only accepts a 2.5 mm mono phono jack. This connector is readily available at most
electronics stores.
The electrical specifications for the interlock input are shown in the following table.
Type of Mating Connector
Open Circuit Voltage
Short Circuit Current
Connector Polarity
Interlock Switch Requirements
Page 8
Specification
Figure 3
Chapter 6: Making the Safety Interlock Connection
Value
2.5 mm Mono Phono Jack
+5 VDC with Respect to Chassis Ground
0.5 mA DC
Tip is +5 V, Barrel is Ground
Must be N.O. Dry Contacts
Under no circumstances should any external
voltages be applied to the Interlock input
Remote Interlock Connector
Ground
+5 Volts
18651-D02