5.8  Wiring to a PLC 
 
PLC 
 
R = max 
500Ω  at 
24 VDC 
 
 
 
 
 
 
 
 
Screen end 
isolated from 
detector and 
earth (ground) 
Screen end 
connected to 
system earth 
(ground) 
 
 
Figure 12.  Wiring to a PLC 
 
Notes 
1.  0-20 mA sinking analogue output, non-isolated. 
 
5.9  Wiring to a 4-20 mA Non-Isolated (Sourcing) Current Output 
The FLS100 detectors can be wired to a 4-20 mA non-Isolated (Sourcing) Output by using the controller’s alarm and fault 
relays, as shown below. 
 
 
Figure 13.  Wiring to a 0-20 mA Non-Isolated (Sourcing) Current Output 
 
The 4-20 mA sourcing output has the following values: 
  ≥4 mA = Normal operation 
  ≥20 mA = Alarm 
  0 mA = Fault (the 0 mA current will change to ≥20 mA (alarm) if flames are detected while the source is in fault) 
Note: 
This configuration has 2 wires connected to T1, but you should check if this is forbidden by your local regulations.