Differences in service life
At the beginning of 2002, a test to determine the service life of profibus cables in a real-world application was commissioned by igus’ test laboratory. The aim was to examine any differences in the service life of igus®’ CFBUS.001 Chainflex® cable and another market-leading profibus cable. The parameters required for the test were selected on the basis of data contained in the competitor’s catalog:
||Test item “A”
|Test item “B”
||(2 x AWG24)C
||(2 x 0.01 inch2)C
||Min. 4 million cycles
||To be determined in
||> = 2.36 inches
||as in 2002
||as in 2002
Test parameters according to catalog data of the competition
A gliding application was chosen as a suitable test structure since profibus cables are usually used here because of their data integrity, particularly over long lengths of travel and long transmission distances.
In order to be able to carry out non-destructive testing and achieve a large number of bending cycles in a short
period of time, a genuine profibus transmission path was
constructed. In a PC at the fixed end of the test cable carrier there was a profibus master-insert card. A connection to a profibus slave was located on the moving end. This enabled the transmission rate to be determined with the help of a diagnosis program. Any data packets which might have been transmitted incorrectly could be indicated. The highest-possible transmission rate of 12 megabits/s was tthereby set.
The fundamental test, which began at the beginning of 2002 and is still in progress today, showed only a
relatively low number of cycles (420,000) resulted in the total failure of test item “A“, which - according to the competitor’s catalog - should have functioned safely for at least 4 million cycles. The actual service life achieved deviates from that indicated in the catalog by a factor of ten.
On the other hand test item “B“, the CFBUS.001, is still undergoing testing without any problems in data transmissions. So far, it has accomplished more than 14 million cycles.