650L Indicator/Safety alarm limit (FM)



  • Gefran 650L Series indicators are designed to interrupt the output in the event that the safety limit of an industrial process is exceeded.
  • Once a limit exceeded event occurs it is latched until reset by an operator acknowledgment action.
  • This reset can be done by the operator from the specific (red R) front key, digital input (optional), or serial line (optional).
  • The displays show the process values, plus multilingual scrolling messages for diagnostics and alarms.
  • The local configuration operation is performed with front panel keys. Permitted key presses are highlighted by their associated LEDs above each key.
  • Easy commissioning is accomplished with a simplified and guided configuration for manual free programming, with only a few required parameters accompanied by intuitive on-display help messages.
  • Using GF_eXpress software with a programming cable and PC, you can program the extended configuration, create recipes and update the firmware without having to switch on the instrument.
  • Thanks to the Smart Configurator function, you can create the initially required parameter recipe by answering a few simple questions. The parameters can always be reset, either from the keypad or from the GF_eXpress software.
  • The device offers complete diagnostics for a broken or an incorrectly connected sensor and has operation counters with settable alarm limits which are useful for scheduling preventive maintenance. A trigger counter and alarm memory reset timer are available for alarm 1. This information can help to evaluate furnace deterioration and plan maintenance work.
  • Maintenance of the system in which the device is installed is made easier by the ability to replace the instrument at any time simply by removing it from the case. No additional steps are needed.


  • Latched Setpoint Alarm relay to interrupt the output in the event that the safety limit is exceeded
  • Alarm output remains latched until acknowledged by operator input
  • Alarm reset from front key, remote digital input or serial communications
  • Alarm limit exceeded count
  • Alarm limit exceeded timer
  • Operator interface with large LCD Display, customizable, with choice of colors
  • Scrolling diagnostics messages, configurable, in the selected language
  • asy guided configuration even with power off using GF_Express Software
  • Multiple password levels
  • Universal input configurable for thermocouples, resistance thermometers, linear or custom inputs
  • Relay, logic and optional outputs
  • RS485 serial communication in Modbus RTU
  • Easy swap case for simple replacement
  • ampling time 60 ms