Johnson Controls FX-PCA4911 - Communications Bus and Supply Power Terminals

Communications Bus and supply power terminal blocks, ratings, and requirements
Table 5: 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
+
-
SA Bus Communications
COM
SA Bus Signal Reference and 15 VDC
Common
SA BUS
SA PWR
15 VDC Supply Power for Devices on the SA
Bus
(Maximum total current draw for SA Bus is
240 mA.)
0.6 mm (22 AWG) stranded, 4-
wire (2 twisted-pairs), shielded
cable recommended.
Note: The + and - wire
are one twisted pair, and
the COM and SA PWR are
the second twisted pair of
wires.
Sensor (Port) Sensor
RJ-12 6-Position Modular Connector
provides:
SA Bus Communications
SA Bus Signal Reference and 15 VDC
Common
15 VDC Power for devices on the SA bus
24 AWG 3-pair CAT3 cable <30.5
m (100 ft)
Ethernet
(Ports)
ETH1
ETH2
Connect to BACnet IP Network
Ethernet ports; 10/100 Mbps; 8-
pin RJ-45 connector
HOT
24 VAC Power Supply - Hot
Supply 20–30 VAC (Nominal 24 VAC)
24~
COM
24 VAC Power Supply Common (Isolated
from all other Common terminals on
controller)
14 VA
0.8 mm to 1.0 mm
(18 AWG) 2-wire
Note: The SA Bus wiring recommendations are
for MS/TP bus communications at 38.4k baud.
For more information, refer to the FX-PC Series
Controllers MS/TP Communications Bus Technical
Bulletin (LIT-12011670).
FX-PCA4911 Advanced Application Controller Installation Guide10