Operator`s manual

a d v a n c e d i l l u m i n a t i o n . c o m

P u l s a r 7 1 0 M a n u a l

Section 8.0 Appendix

Appendix A: NPN / PNP PLC trigger connection

The wiring of the trigger input is dependent upon the trigger source.

Sources can be either “Sourcing” or “Sinking” or both. A sourcing output

(Some times referred to as “Pull Up”) provides an output voltage and must

be connected to a sinking input. A sinking output (sometimes referred to

as “Open Collector” or “Pull Down”) sinks current and must be connected

to a sourcing input. An output that is both sourcing and sinking can be

connected toany typeof input. Sometimesoutputs arecategorized as

NPN or PNP. Usually sinking outputs are NPN and sourcing outputs are

PNP. It is more important to know whether the output is sourcing or

sinking than whether it is NPN or PNP.

Figure 12 shows four common wiring diagrams:

Figure 12-a shows a PLC providing a PNP Sinking Output. The PLC output

is connected to Trigger 1. When the PLC output is activated the trigger

signal will be “Pulled Down” activating the trigger.

Figure 12-b shows a PLC providing a PNP Sourcing Output. The PLC

output is connected to Trigger 2. When the PLC output is activated the

trigger signal will be “Pulled Up” activating the trigger.

Figure 12-c shows a PLC providing a NPN Sinking Output. The PLC output

is connected to Trigger 1. When the PLC output is activated the trigger

signal will be “Pulled Down” activating the trigger.

Figure 12-d shows a PLC providing a NPN Sourcing Output. The PLC

output is connected to Trigger 2. When the PLC output is activated the

trigger signal will be “Pulled Up” activating the trigger.