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TC1540D User's Manual
Rev. 1.2
Figure 8. 4-wire RS-422/RS-485 Connection/Logic Diagram
Pin Assignments and Connection
The removable terminal blocks on the TC1540 factory configured as DCE. The pin assignments for each
type of interface are illustrated below. Pins IN(-) & IN(+) are inputs and Pins OUT(-) & OUT(+) are outputs
(or input/output for 2-Wire RS-485).
Figures 9, 2-wire RS-485 Connection/Logic Diagram
RS-422/RS-485 4-Wire Termination/Connection
Transition
Control
Rcv
User's
Device
W1
Termination
Resistor
120
Ω
-+
TC1540
To/From
Fiber
Tx-
Tx+
Rx-
Rx+
IN-
OUT-
IN+
OUT+
W5
120
Ω
Termination
Resistor
-
+
Drv/Rcv
-
+
SIG
GND
SIG
GND
2-wire RS-485 Termination/Connection
Transition
Control
Drv/Rcv
User's
Device
Tx/Rx+
W5
Termination
Resistor
120
Ω
Tx/Rx-
-
+
TC1540
To/From
Fiber
OUT-
OUT+
SIG
GND
SIG
GND
