BMS
Battery management system. The controller that watches cell voltages, current, temperature, and contactors. Much EV CAN traffic that people want to decode is produced or consumed by the BMS.
CAN
Controller Area Network. A broadcast bus used inside vehicles. Nodes send frames identified by a CAN ID; other nodes filter IDs they care about.
CAN FD
CAN with Flexible Data-rate. Allows payloads longer than 8 bytes and a faster data phase. Some EVs use CAN FD on high-traffic buses. A logger that only speaks classic CAN will mis-read or miss those frames.
CAN ID
The identifier on a CAN frame (11-bit standard or 29-bit extended). In a DBC it is the number on the BO_ line. It is not a signal by itself; it only names the message container.
DBC
A text file that describes messages and signals on a CAN network: bit start, length, endianness, scale, offset, and units. Used by open EV decoding tools to turn hex into physical values.
DTC
Diagnostic trouble code. A stored fault identifier, often read over UDS or older diagnostic protocols. DTCs are not the same as live telemetry on a proprietary CAN ID.
Gateway
An ECU that bridges two or more buses and may filter or rewrite frames. OBD ports often sit on the filtered side of a gateway.
ISO-TP
ISO 15765-2 transport protocol. Segments long diagnostic payloads across multiple CAN frames. Used under UDS.
OBD-II
On-board diagnostics standard. The connector and a set of emission-related requests. It is necessary, but it is not the full EV signal set.
Signal
A named field packed into a CAN payload (for example pack current). Defined in a DBC SG_ line with start bit, length, and scale.
SOC
State of charge. How full the traction battery is, usually as a percent. Display SOC and "real" pack SOC can differ; a DBC should say which one a signal is.
UDS
Unified Diagnostic Services (ISO 14229). Request/response diagnostics on top of CAN (often via ISO-TP): read identifiers, DTCs, routines. Different from unsolicited broadcast telemetry.