SDM54 Series

Introducing the SDM54 Series: The first compact, 3 module, 3 phase, 100A Direct Connected, MID electricity meter for the electric vehicle industry!

Electric Vehicle Charger manufacturing is not only the fastest growing industry globally but, as you would expect, the technology surrounding it is ever evolving at the same speed.

To meet the needs and challenges of the EVC market, Smart Process have decided to stock the SDM54 Series that focuses on electricity metering solutions specifically for electric vehicle charging infrastructure but also comes in handy in any application with limited space.


The SDM54 is a single or three phase, 100A Direct Connected, MID certified, Bi-directional multifunction meter with RS485 Modbus RTU (Two Tariffs optional) in 3 Module DIN rail mounted housing (54mm Wide). Due to its small size, it can easily fit into compact spaces.  The meter can be mounted inside the EV charger to not only measure the electricity used but charge the end user for the electricity consumption. This is perfect for any upcoming or existing EV charging brand who are developing compact new models of their products.




As the meter is typically being used for cost allocation, these meters come alongside the relevant certification under the EU legislation 2014/32/EU (MID). This is great as it allows the EV Chargers to be used in different ways like billing the public within on street charging, billing employees at the workplace or even allowing your charger at home to be used by the public and of course, billing them for their usage.

The SDM54 measures and displays the characteristics of single phase two wires (1p2w) and three phase four wires(3p4w) supplies, including many different parameters such as; voltage, frequency, current, power, power factor, active and reactive energy, imported or exported. Energy is measured in terms of kWh and kVArh. Maximum demand on power and current can be measured over pre-set periods of up to 60 minutes. SDM54 supports max. 100A direct loads per phase, with dual tariff management availability. The meter is designed for DIN-rail mounting, with IP51 front protection. The meter can be optionally equipped with pulse outputs, RS485 Modbus port or M-bus port. Configuration can also be done via keypad, which is password protected.





RS485 Serial–Modbus RTU

The RS485 serial port with Modbus RTU protocol provides a means of remotely monitoring and controlling the unit. Set-up screens are provided for setting up the RS485 port.


The M-Bus port complying with EN13757-3 protocol provides a means of remotely monitoring and controlling the meter. Set-up screens are provided for setting up the M-Bus port.

Pulse outputs

Two pulse outputs that clock up the measured active and reactive energy. The constant of pulse output 2 for active energy is 400imp/kWh (unconfigurable), its width is fixed at 100ms. The default constant of configurable pulse output 1 is 400imp/kWh, default pulse width is 100ms. The configurable pulse output 1 can be set from the set-up menu.

Dual Tariffs

Some meters in this series have dual tariffs function for the cost allocation management. There are two terminal to monitor voltage input from external device. Once there are voltage detected within 230V (80~120%), the energy will be counted in another register.


It should be noted that a Modbus TCP Ethernet version is in development which is aimed to launch in Q1 of 2023.