Are there any internal registers within the BL67 and BL20 that have special functions, e.g first scan etc?

Welcome to MrPLC Graeme! Currently there are no system variables provided, but they are considering adding some. Would you have suggestions as to what they should add?

I recently added a BL20 "Busstop" to a machine with a CompactLogix L32E plc. There is nothing to "heartbeat" the device (to allow a reset function) in case of loss of ethernet communications with the plc. Turck tech support points the finger at A-B and A-B points the finger back at Turck. Fortunately I had a spare input that I directly wired to the terminal strip to give me an "always on" input.