"ex.printStackTrace();" Does exactly what it says: prints a stack trace to the default console (in your case, netbeans console used to deploy). It would not add anything significant to keep that inside of the catch block. (And it would end up being helpful when debugging)
As for whether what you did will work, it completely depends on what you want your code to do when that exception is thrown, so if that is setting the Feed to Relay.Value.kOff, sure.
Something that bugged me a bit in your code is this:
Code:
DriverStationEnhancedIO Cypress = DriverStation.getInstance().getEnhancedIO();
In Java, camel case is standard (see coding conventions -
http://www.oracle.com/technetwork/ja...v-138413.html). This is because accessing static members only requires the class name, which should start with a capital letter. When your fields are named starting with capital letters, it can be hard to distinguish between fields and classes. It's definitely worth starting a habit of camel casing.