Generator and genset monitoring: fuel, load and runtime over Modbus.
A generator failing is rarely a surprise to the machine - it's a surprise to whoever needed the power. Here's what Modbus monitoring actually gives you, and the one alert that matters most.
A generator failing is rarely a surprise to the machine. It's a surprise to whoever needed the power. Low fuel, an overload, a controller fault - the genset usually knows well before the site does, because nobody's watching the one signal that would have told them: the Modbus data the controller has been broadcasting the whole time.
Generator and genset monitoring works differently from telematics on mobile equipment - there's no engine hours ambiguity, no GPS chase, no mixed-brand OEM API problem. It's simpler, and most fleets still don't do it.
Why gensets are the easiest machines to monitor - and the most neglected.
Almost every genset controller built in the last fifteen years - Deep Sea, ComAp, DSE, Woodward and most others - exposes its data over Modbus RTU or Modbus TCP: fuel level, load percentage, output voltage and frequency, coolant temperature, battery voltage, runtime hours, and active alarms. Unlike mobile equipment, there's no need to guess which OEM API to call or whether the machine has a subscription. The controller is already speaking a standard protocol; it just needs to be read.
The reason most generators still aren't monitored isn't technical difficulty - it's that they're often rented, or sit on a site nobody visits daily, or are treated as a background asset rather than something worth a telematics conversation.
What Modbus monitoring actually gives you.
- Fuel level and consumption rate, updated continuously - not read off a dipstick on a site visit
- Load percentage, so you know if a genset is under-sized for the job or running mostly idle
- Output voltage and frequency, flagging instability before it damages connected equipment
- Runtime hours, for service intervals that don't depend on someone logging a start time
- Active alarms and fault codes from the controller itself - low oil pressure, high coolant temperature, battery fault
The alert that actually matters: fuel forecasting.
A fuel gauge tells you the level right now. A fuel forecast tells you when it runs out, based on the actual burn rate at the current load - which is what you need to plan a refill before a site goes dark. On a rented fleet running mixed loads across several sites, this is usually the single highest-value alert: it turns "the tank was empty Monday morning" into a scheduled refuel the Friday before.
Mixed diesel and rented fleets.
Most operators running gensets also run mobile equipment, and increasingly a mix of owned and rented units. The practical requirement is the same one that applies to a mixed diesel-electric machine fleet: one screen, one alerting model, one service-interval logic - not a separate spreadsheet for "the generators" because they don't fit the main fleet dashboard.
What to check before connecting a genset.
- Which controller brand and model is installed - most major brands are supported natively over Modbus, but confirm before assuming
- Whether the site has cellular coverage for the gateway, or needs an antenna extension
- Whether alarms should route to a site contact, a central dispatcher, or both
- Whether the genset is rented - if so, who owns the gateway when the unit goes back
