Led Indicators - Pneumercator MODBUS RTU RS-485 Instruction Manual

1.3.2 Line Termination Resistor
The RS-485 bus requires that the end-of-run device be terminated with a 120-ohm resistor. This is
accomplished by setting the LINE TERMINATION switch to "ON" if the MODBUS Interface Card is
the last device on the bus. Otherwise this switch should be set to "OFF".
MODBUS MASTER
(EXAMPLES: BAS, BMS, PLC)
TERMINAL BLOCK
(SHOWN FOR REF.)
WHT/BL (A+)
BL/WHT (B-)
SHIELD (SHD)
SHIELD WIRE SHOULD
BE CUT BACK AND LEFT
UNTERMINATED
THIS END ONLY

1.4 LED Indicators

Visual indication of Modbus activity is provided by a SLAVE RECEIVE (RX) and a SLAVE
TRANSMIT (TX) LED. Note that SLAVE RECEIVE indicates for all MASTER/HOST transmissions.
MODBUS RTU Instruction Manual - 2017-11-02.docx
MODBUS CARD
(TOP VIEW)
RX
TX
TERM
ON
WHT/BL (A+)
I
BL/WHT (B-)
N
OFF
SHIELD (SHD)
WHT/BL (A+)
O
BL/WHT (B-)
U
T SHIELD (SHD)
2 CONDUCTOR SHIELDED
RS-485 COMM. CABLE
Page 6 of 14
END-OF-RUN
"OFF" POSITION
TO ADD ANOTHER
TMS/LC2000
MODBUS CARD
(TOP VIEW)
RX
TX
TERM
ON
WHT/BL (A+)
I
BL/WHT (B-)
N
OFF
SHIELD (SHD)
O
U
T
SHIELD WIRE SHOULD
BE CUT BACK AND LEFT
UNTERMINATED
THIS END ONLY
November 2, 2017
"ON" POSITION
FOR LAST
TMS/LC2000
DWG NO. 20197 REV. B