
TPU2000/2000R Modbus/Modbus Plus/ Modbus TCP/IP Automation Guide
16
Unicom Physical Interface
Converter Switch Settings
:
- DTE
- RS232-RS485
- 19200 Baud
- HD
Cable “A”
See Attached Diagram
E
C
E
C
E
C
32 Devices and 3000 Feet Maximum loading and distance.
E
C
Unit 1 Unit 2 Unit 31 Unit 32
Three-wire cable with
shield. Cable “B” - see attached diagram.
End Unit Inline Unit Inline Unit End Unit
Jumpers
J6, J7, J8
“OUT”
Topology Diagram for RS485 Multi-Drop Architecture - if external
resistors are installed providing proper termination.
55 56 57 58 59 60 61 -----
475 Ohms
475 Ohms
120
Ohms
AUX Port
* - See note A
* Note A - Following Cable Recommended
Alpha # 58902
Belden # 9729, # 9829
Carol #58902
55 56 57 58 59 60 61 -----
120
Ohms
AUX Port
Figure 3-7. Alternate External Resistor Placement for the TPU2000R
TX +
RX
+
TX -
RX
-
GN
D
3
55 56 57 58 59 60 61 -----
RS485 Isolated Port
Shield is
isolated
Shield is Frame Grounded
at one point
3
55 56 57 58 59 60 61 -----
RS485 Isolated Port
3
55 56 57 58 59 60 61 -----
RS485 Isolated Port
End Unit Inline Unit End Unit
Shield
Isolated
Shield is
isolated
Cable “B” RS485 Connection
*See
Note
*Note - Reference the Topology Drawing
for Termination configuration if internal
or external termination is selected.
Figure 3-8. RS485 Communication Cabling (TPU2000R)
The TPU2000 has the two wire RS485 communication connectivity terminals located in a different position than
that for the TPU2000R. Table 3-2 lists the AUX COM connector signal assignments for the TPU2000.