Siemens POINTEK CLS100 Compact Operating Instructions page 13

Protection Diodes
Always use a protection diode when driving an external relay with the solid state switch
or relay contact. This prevents possible switch damage due to inductive spikes generated
by the relay coil.
Orient the diode based on the current flow.
DC circuit with Protection Diode
enclosure version – see
page 7 for integral cable
equivalents.
7ML19985QJ83
CLS100 controlling the high side of the external relay
(output acts like pnp transistor switch)
external relay
CLS100 controlling the low side of the external relay
(output acts like npn transistor switch)
Pointek CLS100 – QUICK START MANUAL
DC
protection diode
(customer supplied)
Page EN-11