Hello Lee;

Both types of connectors do their job properly, depending on the environment they are working in and on the quality of the installation.

For example, screw-type connectors have been lnown to lose contact under hign mechanical vibration on the Profibus slave. And fast-connect systems have been known to not quite pierce the wire insulation properly (an installation defect) thus making the connectin prone to failure.

But the most important thing is to implement the use of certified Profibus cables (of the right type for your application)in your plant with the connectors you choose and to teach the proper installation techniques of the connectors by your technicians. Also, show them how to test the connection setup properly before they finish the installation. This will improve the chance that connections will not fail due to cable and connector failure.

Hop this helps,

Daniel Chartier