Ingersoll-Rand ReliaTel, Manual, Page: 117 / 176

RT-SVD03L-EN 117
COMM3/4 Interface
Operation & Troubleshooting
Wiring
The COMM3/4 board communicates with the RTRM via
the MODBUS link using the harness, labeled 4366-1151.
The connections to the board are shown below.
Communication wires must be twisted/shielded as
specified by the BAS system being applied. Do not
attach the shield to the COMM3/4 board. It must be
taped back to prevent it from touching the unit.
LED’s
Amber receive (RX) LED: Blinks whenever
communication is occurring with any device. This tells
the service technician that the BAS system is
communicating or trying to communicate with other
devices as well as this one.
Green transmit (TX) LED: Blinks once every several
seconds, sometimes up to 45 seconds between blinks,
when the unit is sending data to the BAS system. This
tells the service technician that this unit is
communicating information to the BAS system. When
the TX LED is blinking, the unit is communicating.
Communication Problems
Figure 71. Troubleshooting outline
COM LINK board
shown in
"Non-isolated
COMM3 or
COMM4 position"
Communication
wiring
DIP Switches
LED's
Shield
taped
back
COM LINK board shown
in "Isolated COM 3"
position
To options
module &
economizer
Zone Sensor
used with
Tracker and
Tracer
Setpoint
Zone
temperature
RTR M
J4
This harness
labeled 4366-1151,
is supplied with the
COMM3/4 interface
J1
J2
T
B
1
J1
J2
T
B
1
T
X
R
X
3
2
1
Won’t Communicate with Tracker ® ® - 3 to 25
Tons Only
• Harness, labeled 4366-1151, must be plugged into
RTRM correctly – see previous page.
• Com Link board must be in “ISOLATED COM 3”
position. If it is in the wrong position or not
installed, the unit will not communicate.
• Each unit must have a unique address by setting
the DIP switches according to the IOM. If 2 units
have the same address, neither will communicate. If
the unit has a DIP switch setting other than the ones
specified in the IOM, Tracker
® will not recognize it.
• Once the unit communicates with Tracker ® , the
Tracker ® panel will automatically recognize the
unit.
• Resistor missing at last unit in daisy chain
(depending on length of line run).
Won’t Communicate with Tracer ® ® Summit
• Harness, labeled 4366-1151, must be plugged into
RTRM correctly – see above.
• Com Link board must be in “NON ISOLATED
COMM3 or COMM4” position. If it is in the wrong
position or not installed, the unit will not
communicate.
• Each unit must have a unique address by setting
the DIP switches according to the IOM. If 2 units
have the same address, neither will communicate. If
the unit has a DIP switch setting other than the ones
specified in the IOM, Tracer
® will not recognize it.
• Once the unit communicates with Tracer ® , the
Tracer ® panel will automatically recognize the unit.
Won’t Communicate with VariTrac ® ® CCP
Zoning System
• Harness, labeled 4366-1151, must be plugged into
RTRM correctly – see above.
• Com Link board must be in “NON ISOLATED
COMM3 or COMM4” position. If it is in the wrong
position or not installed, the unit will not
communicate.
VariTrac ® ® I Comfort Manager and VariTrac ® ®
II Center Control Panel
• The DIP switches must all be in the ON position. If
not, the VariTrac
® CCP will not recognize it.
• The communication wires must be in the same
daisy chain link as the dampers.
• VariTrac ® III central control panel (optional touch
screen) — All DIP switches must be in the off
position. If not, the VariTrac
® CCP will not
recognize it.
Communicates but Will not Run, even in
TEST Mode
• Emergency stop input is open (RTRM 3J1-12).
Communicates but Will not Run; Fan Runs in
TEST Mode for 40 Seconds Only (but no
Heating or Cooling)
• 3 to 25 tons - Fan proving circuit (RTOM 5J7-6) is
closed; should open when fan is on. If not, the fan
will run in TEST mode for 40 seconds and then
stop.