CMC 256plus

High precision relay test set and universal calibrator

The reference for accurate signal requirements

The CMC 256plus is the first choice for applications requiring very high accuracy. This unit is not only an excellent test set for protection devices of all kinds but also a universal calibrator.

Its high precision allows the calibration of a wide range of measuring devices, including: energy meters of class 0.2, measuring transducers, power quality measurement devices and phasor measurement units (PMU).

Its unique accuracy and flexibility make the CMC 256plus ideal for protection and measurement equipment manufacturers for research and development, production and type testing.

Key features

  • Protection test set and universal calibrator in one device
  • Testing of all relay generations – electromechanical, static, numerical, IEC 61850
  • Highly accurate test signals. For meter testing: The sources are the reference – no additional reference meters are required
  • Integrated network for testing IEC 61850 IEDs
  • 10-channel analog measurement and transient recording functionality (option)

LLO-2 Hardware Option

This option adds additional 6 low level outputs to the CMC 256plus. The total amount of generators that can be controlled by the test set is extended from 16 to 22. The low level outputs can be used to directly test relays with low level inputs or can be used to control additional external amplifiers such as the CMS 356.

The low level outputs can simulate signals from non conventional CTs and VTs with low level interfaces. Unique is that Rogowski-coil signals can be simulated not only steady state but also for transients.

Solutions for:


Testing meters & transducers

Maintenance and commissioning of protection relays: CMC 256plus

Testing of protection and measurement equipment




February 25 - 27, 2020
Training Center Erlangen, Erlangen, Germany
CMC Product Family, IEDScout / SVScout, DANEO, ISIO
February 25 - 27, 2020
Training Centre Stafford, Stafford, United Kingdom
CMC Product Family
March 2 - 4, 2020
Training Center Melbourne, Melbourne, Australia
CMC Product Family

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