BusWorks®
961/962PB Module User’s Manual ProfiBus Differential I/V Input
___________________________________________________________________
_______________________________________________________________________________________
Acromag, Inc. Tel:248-624-1541 Fax:248-624-9234 Email:
http://www.acromag.com
9
All activated terminations must be powered all the time. If this is not
possible, then consider using an active-termination box.
Check whether the station address is set to the correct value.
If your network connects between buildings or runs through
hazardous environments, consider the use of fiber-optics.
Avoid drop lines and keep their length within the specified maximum.
For T-drops, consider using repeaters and active-bus terminations.
1. Incorrect slave address set at the slave.
2. ProfiBus connector between the master and slave has its
termination switch turned ON.
3. Incorrect module configuration sent to slave.
4. Configuration is based on outdated GSD file information.
There are several models of handheld devices on the market that
simplify the installation and troubleshooting of ProfiBus networks. The more
sophisticated units include LCD displays that read out errors directly. Two of
these of these devices are referenced below:
Hand-Held ProfiBus Network Maintenance Tools
Manufacturer
Part Number
Special Features
Siemens
BT 200
Primarily a Cable Tester
Comsoft
NetTest II Set
4000-7-06C-J
Includes DP Mono-Master
Functionality
In general, these devices can be used to check the network wiring
before devices are connected to the bus and are often used to indicate:
Whether the A and B lines have been switched.
Whether a short exists between the A & B lines and shield.
The occurrence of a wire-break in the A or B line, or shield line.
Improper termination.
These devices can also be used to check the RS-485 interface of
ProfiBus devices after they have been connected. They may include the
following functions:
The ability to create a list of all stations connected to a network
(useful for identifying missing or “offline” devices).
Test individual stations and help identify duplicate addresses.
Measure the distance along a network segment to verify whether it
complies with the Profibus requirements for distance and data rate.
Detect signal reflections along the network, useful for locating bus
line interruptions and discontinuities.
Acromag strongly suggests the use of these tools for building and
maintaining ProfiBus networks.
Note that Profichip also offers a Profibus connector (PA003100) that
includes 4 network diagnostic LED’s that may be helpful in trouble-shooting
your network (see table below).
Tips For Building
ProfiBus Networks
Top Four Common
ProfiBus Problems
Troubleshooting Tools
