Edwards Signaling eFSA250 - Manual (Page 24)

Chapter 1: Installation and wiring
12 E-FSA64 and E-FSA250 Technical Reference Manual
Figure 14: Device loop wiring location
Figure 15: Class B wiring (Style 4)
A
Loop card
+
–
B
+
–
Loop
device
Loop
device
Data line
Figure 16: Class A wiring (Style 6)
Loop 1 SEC
+
–
Loop 1 PRI
+
– +
– +
–
Loop
device
Loop
device
Loop card
SLC
Figure 17: Class A wiring (Style 7)
Loop SEC
+
–
Loop PRI
+
–
Loop card
Loop
devices
Isolator
module
Isolator
module
UL/ULC listed enclosure
Data line
Loop devices
with isolator base