Siemens GS..D.. Bedienungsanleitung PDF herunterladen (Seite 28)

How to configure an Anybus PROFIBUS Slave module with a Siemens Step7 PLC

SCM-7032-026

Rev 2.1

www.anybus.com HMS Industrial Networks AB

Page 28 (30)

Appendix 3 Troubleshooting network physics

The most common failure when the diagnostic tool reports “nonsense” is physical errors on the network like

cable connect errors, miss contact, wrong termination etc. Some simple ways to find these errors will be

mentioned here.

Data errors can occur if the PROFIBUS cable is incorrectly attached to the bus connectors. Such basic errors

can be detected and remedied with the simple test method described below. The test method shown

schematically in Figure 34 allows you to detect data wires which are swapped over in the bus connectors.

During the test, the bus connectors must not be connected to any PROFIBUS devices. In addition, all bus

terminating resistors should be removed or disabled. The tests require two 9 pin female Sub-D test

connectors. Test connector 1 is provided with a single pole changeover switch, the moving contact of which

is connected to the shield (case) of the test connector. The two fixed contacts are connected to pin 3 (data

wire B) and pin 8 (data wire A), respectively. Test connector 2 is used to connect an Ohmmeter to the bus.

During the cable tests, the two test connectors 1 and 2 are initially plugged into the two bus connectors at

each end of the bus segment. The following tests can be made by taking measurements between the contacts

3 and 8 and the shield of test connector 2 while operating the changeover switch on test connector 1:

• Data cable swapped over

• Open circuit of one of the data cables

• Open circuit of the cable shield

• Short circuit between the data cables

• Short circuit between the data cables and the cable shield

• Additional bus terminating resistors inserted unintentionally

1 2 ... 23 24 25 26 27 28 29 30

Keine Kommentare

Siemens GS..D.. Bedienungsanleitung Seite 28