Pacer compatability?

[trc666]

The 170s are 100mph units and they worked in multiple with 90mph 159s all the time when they were at SWT.

142s can certainly run in multiple with 153s as I in fact travelled on that very combination from Newton Abbot to Torquay a few months back (the 153 being London Midland liveried).

 

[driver9000]

There probably is for the unit itself (Pendos have TASS, not sure about other units)
However, there is a limit to how many iterations of potential variations can be reasonably programmed in so say couple a 153 to a 170 and the 170 probably doesn't know it has a 75mph only capable unit stuck to the back of it (could be another 170 for all it knows) and so probably wouldn't limit it down (assuming such systems are in place, of course)

No speed limiters fitted. There is no way for that information to be transmitted on coupling either.

However some of the most recently built units may have governors, 185s for example do.