Quite likely it is a specialized piece of test equipment used to time circuit breakers.
I haven't worked in the field for years, so I could very well be wrong. We used to have to time circuit breakers from the time they received trip signals from relays until the main and auxiliary contacts operated.
It possibly counts cycles, or 1/60 of a second.
If the operation was delayed too long, the Breaker Failure relays would operate and trip an auxiliary relay to open all of the rest of the breakers on the bus. Instead of losing just the customers on one circuit, you would then lose all the customers being served from that substation.
We also tested for other operating conditions like "minimum trip voltage", which would tell us how low the station battery could get before we would lose the ability to open up circuit breakers.
I say "specialized" because I can't see where the data inputs plug into the device, and it might be used on only one brand of circuit breaker. Call the power company and ask them if they are interested in recovering their property!