Siemens SIMATIC NET PROFIBUS manual How the Unit Functions

Testing PROFIBUS

A.1.6 How the Unit Functions

Testing Cables

The previously described tests and measurements are based essentially on various voltage, reflection and resistance measurements. To check the cable, the test unit is connected to one end of the cable and a test connector at the other. When installing the cable, the user works gradually from connector to connector. At the press of a button the measurements are made automatically and the test results displayed.

Tests on Nodes

When testing on the node itself, a point-to-point link is established between the test unit and the node. To complete the tests, the accessibility of the attached slaves is checked on the wired-up bus. The user can have a list of accessible slaves created automatically or can check the accessibility of a single slave by specifying its address manually.

Displaying the Test Results

Apart from the actual test result, the display also indicates concrete measures that can be taken to remedy problems. During the measurement of the reflections, the location of the problem is also displayed. This means that the user does not require specialized PROFIBUS knowledge to work with the test unit and to find typical problems in the wiring and setup and to eliminate them. No additional devices are necessary for the measurements. This means a drastic reduction in commissioning times and plant downtimes.

Documenting the System Status

The BT200 simplifies the creation of an acceptance report to document the system status at the time of acceptance. As standard, the unit is designed for operation on PROFIBUS cables complying with type A (EN 50170). The unit parameters can, however, be modified by entering the electrical parameters for the cable to be tested. This means (whatever cable type is used) that the location of a problem can be displayed in meters as well as the total length of the installed cable.

Battery Operation

The device has an accumulator battery. This ensures that the user can test the entire system regardless of the network. The unit is turned off automatically after 3 minutes if no input is made ensuring that the battery has a long working life and saving power.

PROFIBUS Networks SIMATIC NET	A-5
6GK1970-5CA20-0AA1 Release 2 05/2000