On-board weighing and overload protection is used for trucks, off-highway, or off-road vehicles. The CiA 459 series specifies the CANopen CC interface for such devices. It distinguishes three classes:

• Class 1: Devices are capable of monitoring the loaded vehicle weight, might be capable of monitoring the loaded axle weight, and provide monitored weighing data.
• Class 2: Devices are capable of performing non-LFT (legal-for-trade) transaction weighing and provide non-LFT transaction weighing data
• Class 3: Devices are capable of being fully certified as LFT and of performing LFT transaction weighing. Class 3 devices might additionally support the capabilities provided by class 1 and class 2 devices. The LFT capable device must have at least one alibi component: either alibi memory or an alibi printer.

On-board weighing devices with load-monitoring capability observe the total vehicle or trailer load and weigh optionally the load on a single axle or a group of axles. Devices supporting non-LFT and LFT transaction weighing store optionally the weighing data in an internal or external data storage device (DSD).

The on-board weighing device can perform load monitoring and transaction weighing at the same time. In case, the on-board weighing devices require switching between load monitoring modes and transaction modes, the switch is performed by setting the mode in the operating mode object. The on-board weighing device can provide the status of the on-going transaction weighing, when switched into transaction weighing, depending on the configured PDO mapping. It is highly recommended that transaction weighing data is read from the DSD or alibi memory whilst the device is in the NMT state pre-operational. An on-board weighing device uses one or more load cells to do the weight measuring. These load cells are either connected by means of discrete ports or serial interfaces such as sub-layered CANopen CC networks.

The CiA 459 series and the CiA 413 series are only available for members. CiA 459-1 provides general specifications and an overview of the functions. CiA 459-2 specifies the communication parameters including PDO mapping. CiA 459-3 defines in detail all process data and application configuration parameters.