One of the consequences of the integration of renewables is a sharp acceleration in the development of smart grids. The restructuring this brings and the growing dynamism of electricity supply systems have led to a steady increase in the importance of constant and reliable power systems monitoring.

A multitude of parameters have to be monitored in order to assess the security of supply and the power quality of an electrical power system. These parameters must provide vital information for the fast and effective restoration of system operation when a fault occurs, as well as serving as the basis for the extension of power systems and the optimisation of primary and secondary technology.

The wide-ranging requirements to be met by efficient power systems monitoring and the cost pressures acting on the installation and operation of supply equipment call for the use of multi-functional measurement and analysis systems. The SHERLOG CRX fault recorder system has been developed to meet these requirements and unites all the necessary monitoring functions in one device.

Customized systems, compact and flexible

SHERLOG CRX is a multi-functional measurement and analysis system for comprehensively monitoring and assessing equipment in electricity supply systems.

Because of the modularly scalable device concept, SHERLOG CRX can be equipped to suit individual requirements and can easily be adapted or extended should these requirements change.

Despite its compact size, SHERLOG CRX can be equipped with up to 32 analog inputs for AC and DC measurements and up to 128 binary inputs. Individual devices can be interlinked via a coupling interface to monitor extensive installations.

Simple to modify configuration

All analog inputs can be used for current measurement, for voltage measurement or for measuring low-level signals. The appropriate measuring ranges can easily be selected on site by customers.

Plug & Play technology

Extensions can be realized quickly and easily thanks to Plug & Play technology. Even swapping an entire module does not involve time-consuming, expensive adjustments, as the calibration data is saved in the module.

Dual-processor system

SHERLOG CRX features separate processors for the user interface and the communications interfaces. This innovative technology guarantees easy operation, fast data transmission and simultaneous data access for more than one user or application at a time - all the time.

Safe to operate even under extreme conditions

Because SHERLOG fault recorders contain no parts which are subject to wear and tear, such as hard disk memories, fans or UPSs, they are 100% maintenance-free and extremely safe to operate. 

Their excellent immunity to electro-magnetic disturbances also ensures smooth operation even when conditions are extreme. What is more, all interfaces and all analog and binary inputs and outputs are galvanically isolated. Not only does this guarantee safe functioning, it also makes for a safe working environment.

Internal flash memory

SHERLOG CRX is equipped with a 2 GB flash memory. This large memory capacity enables measured values and faults to be recorded at a particularly high resolution over long periods of time, even when there is no permanent data connection to a mass storage medium (server).

Measurement data is saved reliably and cannot be lost, even in the event of a power failure or when the device is switched off.

Communication interfaces

SHERLOG CRX features the following 

communication interfaces:

  • Electric Ethernet
  • Optical Ethernet (optical fibre)
  • USB (active/passive)
  • RS 485
  • RS 232
  • GSM/GPRS modem
  • UMTS router

Time synchronisation

Power system monitoring and fault analysis with full area coverage call for precise time synchronisation. Only when measured values are recorded by a number of devices absolutely simultaneously is it possible to compare them with one another and evaluate them correctly. SHERLOG CRX can use all conventional methods of time synchronisation.

  • GPS synchronisation with internal receiver
  • GPS synchronisation with an external central clock
  • DCF77
  • NTP/SNTP
  • IRIG-B
  • Synchronisation to PC time
  • Seconds and minutes pulse
  • KoCoS-Interlink interface

Using the KoCoS-Interlink interface, any number of devices can be synchronised with one another using a simple 2-wire connection or fibre-optic loop. This results in a significant reduction in costs as only one measuring device per location needs to be synchronized as the "master" system.