A fleet report mixes three vocabularies: the shop’s, the engine computer’s and the software’s. These are the 40 terms we use most on this site, each in a sentence or two, with a link to where it shows up in our work.
Terms from A to Z
- AEMP 2.0
- The second version of the telematics data standard from the Association of Equipment Management Professionals, which lets one system read machine data from many manufacturers. ISO 15143-3 grew out of it.
Where this shows up in our work - After-hours alert
- A message sent when a machine starts or moves outside the working hours set for its job. It is often the first sign of theft or unauthorized use.
Where this shows up in our work - API
- Application programming interface: a documented way for another system, such as your accounting software, to read and write fleet data. Gytix’s API is part of the Command plan.
Where this shows up in our work - Asset health score
- One rating per machine that rolls up active fault codes, overdue services, inspection defects and recent repairs. It sorts the fleet so the shop looks at the worst machines first.
Where this shows up in our work - Backhaul
- The return trip of a truck or lowboy, loaded instead of empty. Planning moves so the lowboy brings another machine back saves a trip.
Where this shows up in our work - Bluetooth tag
- A small battery beacon fixed to a tool or attachment and read by nearby gateways or phones. The Gytix T1 tag runs up to three years on its battery.
Where this shows up in our work - CAN bus
- Controller area network: the wiring that lets a machine’s engine, transmission and hydraulic controllers share data. A telematics gateway listens on it for hours, fuel and fault codes.
Where this shows up in our work - DEF
- Diesel exhaust fluid, a urea solution injected into the exhaust of many Tier 4 Final engines to cut nitrogen oxides. Running low or using contaminated fluid can derate the engine.
Where this shows up in our work - DPF
- Diesel particulate filter: a filter in the exhaust that traps soot and burns it off during regeneration. Ash that does not burn off is cleaned out at a set service interval.
Where this shows up in our work - Duty factor
- A multiplier that brings service intervals forward for machines working in heavy dust, heat or load. It shortens intervals and never stretches them past the manufacturer’s manual.
Where this shows up in our work - DVIR
- Driver vehicle inspection report. Federal rule 49 CFR 396.11 governs these reports for commercial motor vehicles, and 49 CFR 390.32 allows them to be created and kept electronically.
Where this shows up in our work - Fault code
- A diagnostic trouble code a controller sets when a reading falls outside its limits, such as low oil pressure or a failed sensor. On J1939 engines it combines an SPN, an FMI and an occurrence count.
Where this shows up in our work - FMI
- Failure mode identifier: the part of a J1939 fault code that says how a reading failed, such as above normal, below normal or an open circuit. Under SAE J1939-73 it is 5 bits long.
Where this shows up in our work - Gateway
- The tracker wired to a powered machine that reads engine data and GPS and sends them by cellular or satellite. Gytix’s A1 runs on 9 to 36 volts and stores 30 days of data offline.
Where this shows up in our work - Geofence
- A boundary drawn on the map around a job, yard or lease. Arrivals, departures and after-hours movement inside it are logged against that place.
Where this shows up in our work - Hour meter
- The gauge that counts a machine’s engine running hours, the clock most service intervals and rental contracts run on. Telematics reads the same count from the engine controller.
Where this shows up in our work - Idle time
- Engine hours with the engine running and the machine doing no work. It burns fuel and adds hours to the meter without moving any dirt.
Where this shows up in our work - ISO 15143-3
- ISO/TS 15143-3 specifies a web-service schema for sending machine status data, such as location and operating hours, from a telematics provider’s server to other applications. It grew out of the AEMP telematics standard.
Where this shows up in our work - J1939
- The SAE family of standards that defines how heavy-duty diesel engines and controllers talk over the CAN bus. SAE J1939-73 sets how fault codes are built.
Where this shows up in our work - Job costing
- Charging each machine’s hours, fuel and repairs to the job where they happened. Engine hours logged by geofence make the job cost match the machine.
Where this shows up in our work - Lowboy
- A trailer with a deck set low between the gooseneck and the rear axles, used to haul heavy machines. New Mexico State Police policy requires an oversize permit for a vehicle and load over 14 feet high.
Where this shows up in our work - LTE-M
- A low-power form of LTE cellular built for trackers and sensors that send small amounts of data. Gytix’s A1 gateway reports over LTE-M.
Where this shows up in our work - MCP
- Model Context Protocol, an open standard for connecting AI assistants to outside tools and data. Gytix’s MCP server lets assistants your team already uses query fleet data and draft work orders, with the user’s own permissions.
Where this shows up in our work - Min/max
- A reorder rule for parts: when stock falls to the minimum, order enough to bring it back to the maximum. It keeps filters and wear parts on the shelf without filling the shop.
Where this shows up in our work - MTBF
- Mean time between failures: the average running hours between unplanned breakdowns of a machine or component. A falling MTBF on one model is a warning worth reading.
Where this shows up in our work - MTTR
- Mean time to repair: the average time from a breakdown until the machine works again, waiting for parts included. It shows whether the shop or the parts shelf slows recovery.
Where this shows up in our work - OC
- Occurrence count: the part of a J1939 fault code that counts how many times the fault has happened. Under SAE J1939-73 it is 7 bits long.
Where this shows up in our work - Off-rent
- The point at which a rented machine is called off and stops billing. Rental days that run past the end of the work because nobody called the machine off are pure cost.
Where this shows up in our work - Oil analysis
- Lab testing of an oil sample for wear metals, dirt, fuel and coolant. Regular samples from the engine, hydraulics and drives catch wear before it becomes a failure.
Where this shows up in our work - Owning and operating cost
- The full cost of a machine per hour: owning costs such as depreciation, interest and insurance, plus operating costs such as fuel, repairs, tires and wear parts. It is the honest number for rent or own decisions.
Where this shows up in our work - PM
- Preventive maintenance: scheduled service done by hours or calendar before something fails, such as the 500-hour oil and filter change. A PM plan lists the tasks for each interval.
Where this shows up in our work - PTO hours
- Hours a power take-off runs, driving a pump, blower or other equipment while the truck stands still. Counting them apart from road hours keeps service schedules and fuel reports accurate.
Where this shows up in our work - Regeneration
- Burning trapped soot out of a DPF, either passively while the engine works hard or actively with added heat. Interrupting active regenerations again and again leads to a plugged filter.
Where this shows up in our work - Right-sizing
- Matching the number and type of machines to the work the fleet actually does, by selling, swapping or renting. It starts with utilization and owning cost per machine.
Where this shows up in our work - SPN
- Suspect parameter number: the part of a J1939 fault code that names what is wrong, such as engine oil pressure or coolant temperature. Under SAE J1939-73 it is 19 bits long.
Where this shows up in our work - Store-and-forward
- A tracker’s habit of saving readings while it has no signal and sending them all once it reconnects. The A1 gateway holds 30 days of data this way.
Where this shows up in our work - Telematics
- Collecting data from a machine, such as location, hours, fuel and fault codes, and sending it to software by cellular or satellite. The word joins telecommunications and informatics.
Where this shows up in our work - Tier 4 Final
- The last stage of the EPA’s Tier 4 emission standards for nonroad diesel engines, adopted in 2004 and phased in from 2008 to 2015. Many Tier 4 Final machines use a DPF, DEF or both to meet it.
Where this shows up in our work - Utilization rate
- Hours a machine worked divided by the hours it was available. A machine that ran 20 of 50 available hours in a week was 40% utilized.
Where this shows up in our work - Work order
- The shop’s record of a job: the machine, the tasks, the parts, the mechanic, the hours and the sign-off. In Gytix, a PM work order opens 50 hours before the interval by default.
Where this shows up in our work
See these terms on your fleet
On a walkthrough we show hours, fault codes and utilization for machines like yours, explained in plain English or Spanish.