5803641-JIM-B-0620
Johnson Controls Ducted Systems
57
CANCEL
Button for display menu navigation and zeroing of
active compressor ASCD timer
JOY
4-way Joystick for display menu navigation
Item USB connector at right of UCB
J10
Type A female Universal Serial Bus connector
Used for backup, restoration, & copying of board parameters as
well as board software updating through a flash drive
J15
Factory wired SA Bus connector
Optional communication sub-board at center of UCB
Terminal FC BUS
1
connections on left edge of the communication board
FC+
FC (“Field Connected”) BUS BACnet MSTP
communication
Positive of the VDC (typically, a fluctuating 1.5 to 3.5 volts
reading to COM; at least 0.25 volts higher than
–
) FC bus
BACnet MSTP communication circuit
FC–
FC (“Field Connected”) BUS BACnet MSTP
communication
Positive of the VDC (typically, a fluctuating 1.5 to 3.5 volts
reading to COM; at least 0.25 volts lower than +) FC bus
BACnet MSTP communication circuit
COM
Common for the FC (“Field Connected”) BUS
BACnet MSTP communication circuit
Negative of the VDC FC bus BACnet MSTP communication
circuit
SHLD
Shield for the FC (“Field Connected”) BUS
BACnet MSTP communication circuit
Earth ground reference of the cable to prevent interference on
the FC bus BACnet MSTP communication circuit
Item Selector in red housing at left on top edge of the communication board
EOL
switch
End Of Line selector switch for the FC BUS
BACnet MSTP communication circuit
ON selected only for the UCB that is the terminus of the FC bus
BACnet MSTP communication cable to prevent signal “bounce-
back”
LEDs on the communication board
EOL
Green End Of Line indicator
Lit indicates the EOL switch is selected ON
FC BUS
Green FC bus communication transmission
indicator
Lit/flickering indicates outgoing UCB FC bus communication is
currently active, off indicates the UCB is awaiting incoming FC
bus communication
ISO PWR
Green communication board Isolated Power
indicator
Lit indicates the UCB is supplying power to the communication
sub-board
1. When wiring unit and other devices using the SA Bus and FC Bus, see Table 30.
Table 29: Smart Equipment™ UCB Details (Continued)
Description
Function & Comments
