
Table 4: Communications bus and supply power terminal blocks, functions, ratings, requirements, and cables
Terminal block/
Port label
Terminal
labels
Function, electrical ratings/Requirements
Recommended cable type
HOT
24 VAC Power Supply - Hot
Supplies 20–30 VAC (Nominal 24 VAC)
24~
COM
24 VAC Power Supply Common
(Isolated from all other
Common terminals on controller)
35 VA
0.8 mm to 1.0 mm
(18 AWG) 2-wire
Note:
The SA Bus and FC Bus wiring
recommendations in this table are for MS/TP
bus communications at 38.4k baud. For more
information, refer to the
MS/TP Communications
Bus Technical Bulletin
(LIT-12011034)
for detailed
information about wire size and cable length
requirements for the SA and FC buses.
Metasys
System FEC1611 and FEC1621 Field Equipment Controller Installation Guide
9