Datalogic SG4 FIELDBUS Series, Instruction Manual, Page: 37 / 136

NOTES ON CONNECTIONS
INSTRUCTION MANUAL 27
NOTES ON CONNECTIONS
For the correct operation of the safety light curtains, the following precautions regard-
ing the electrical connections have to be respected:
• Do not place connection cables in contact with or near high-voltage cables and/or
cable undergoing high current variations (e.g. motor power supplies, inverters,
etc.);
• Do not connect the OSSD wires of different light curtains in the same multi-pole
cable.
- The TEST wire must be connected through a N.O. button to the supply voltage
of the ESPE.
• The device is already equipped with internal overvoltage and overcurrent suppres-
sion devices.
• The use of other external components is not recommended.
Example: connection to the safety relay SE-SR2
Figure 6 - Connection to SE-SR2 Safety Relays
The figure shows the connection between the safety light curtains and the safety relay
of the SE-SR2 series functioning in the Automatic Restart mode (left side) and Manual
Restart with monitoring (right side).
• Do not use varistors, RC circuits or LEDs in parallel at relay inputs or in series at
OSSD outputs.
• The OSSD1 and OSSD2 safety contacts cannot be connected in series or in parallel,
but can be used separately, conforming to the plant’s safety requirements.
CAUTION
The TEST button must be located in such a way that the operator can check
the protected area during any test.
The RESET/RESTART/ALIGN button must be located in such a way that the
operator can check the protected area during any reset operation.