Troubleshooting - ABB TPU2000 Technical Manual

TPU2000/2000R Modbus/Modbus Plus/ Modbus TCP/IP Automation Guide
Table 1 - RS485 Communication Card RS485 Cross-Reference List
PIN
DESIGNATION
+ 5 VDC
RS485 Common
RS-485 (-)
RS-485 (+)
Wire attachment on an RS 485 TYPE 8 card's COM 3 DB 9 port can be tricky in an in-line installation. ABB has a
special connector, which changes the female DB 9 port into a PHOENIX contact 9-pin connector (similar in format
to the AUX COM PORT). The ABB part number of this 9 Pin male to Phoenix Card Connector is ABB part
602133-009. The same part is also available from Phoenix Contact and the part number is 27 61 50 9.

Troubleshooting

The TELEBYTE RS 232/RS485 converter Model Number 245 has the advantage of four LED's present at the side
of the unit (as indicated in Figure 1) indicating RS232 port transmit data, RS232 port receive data, RS 485 port
transmit data and RS 485 port receive data. Visual indication of these LED's should allow the implementor to
troubleshoot a unit, which does not communicate at all.
If communication messages do not appear to be transferred from the RS 232 port to the RS 485 port, one should
investigate wiring, DTE/DCE emulation switches, and the wiring on the RS 232 and RS 485 ports.
If the error rate of communication message transmission and reception is high, investigate wiring in the areas of:
1. Biasing of the cable in only one location.
2. Installation of termination resistors at two nodes only (at both remote ends).
3. Cable installation with three wires AND A SHIELD. REMEMBER SHIELD IS NOT GROUND.
4. DAISY- CHAINING the RS 485 wiring so no in-line stubs, taps, and junction strips are inserted in the unit.
5. Incorrect installation of the Shield (connected at in line nodes and isolated at ground).
6. Incorrect lengths of RS 485 or RS 232 cables (3000 feet = RS 485 or 50 feet = RS 232).
7. Incorrect selection of "handshake control" for operation with the IED or Host (ABB IED's do not employ
handshaking. Some hosts require RTS/CTS handshaking or the CD and DTR signal must be looped back in
the cable.)
Conclusion
There are many converters available on the market.
manufacturers' physical interface converters.
implementor's knowledge of the software control of the physical interface, IED physical interface operation and
knowledge of the particular brand of converter.
Contributed by:
John Popiak
Revision 0, 03/01
COM 3 TYPE 8 COM
PORT (2000R Family)
8
7
2
1
AUX COM PORT
(2000R Family)
60
57
56
55
Successful communication can result in using many
Success in implementing a physical interface relies on the
AUX COM PORT
(2000 Family)
77
74
73
72
364