Gefran 40TB Display & Alarm Unit
The Gefran 40TB is a microprocessor-based unit, 96×96 mm (1/4 DIN), designed for process indication and alarm management. It features two independent input channels and up to three programmable alarms. This device is not a PID controller; it is used for measurement, display, and alarm handling in pressure, force, temperature, or linear signal applications. The front panel is rated IP65 and includes two 4-digit LED displays and a bargraph.
Measurement Inputs
Channel 1 accepts strain gauge sensors for pressure or force, with 5 or 10 V excitation and sensitivity from 1.5 to 7.5 mV/V. Potentiometer input is also supported, with 1.2 Vdc excitation. Channel 2 supports TC, RTD, PTC, NTC, and analog signals (60 mV, 1 V, 5 V, 10 V, 20 mA).
Sampling and Scaling
Sampling rate is adjustable from 15 to 120 ms. At 120 ms, resolution reaches 16,000 divisions; at 15 ms, response is faster with reduced resolution. Linear scaling is configurable from -1999 to 9999, with 32-segment linearization available.
Outputs and Alarm Logic
Up to three relay outputs (5 A / 250 V) or static outputs (0–11 Vdc) are available. Alarm thresholds can be set as absolute or relative, with direct/reverse logic, hysteresis, startup masking, latch reset, and programmable delays (DON/DBI/DOF/DPO). Two digital inputs are provided for reset, hold, flash, peak, and memory reset functions.
Retransmission and Communication
Optional analog retransmission outputs (10 V or 20 mA) are available for input signals, alarm setpoints, gross/tare, or peak values. Serial communication supports Current Loop, RS422/485, or RS232, with GEFRAN CENCAL or Modbus protocols up to 19200 baud.
Typical Applications
- Pressure indication from strain gauge transducers
- Force measurement in presses and test benches
- Temperature display in thermal processes
- Over/under pressure or force alarms
- Measurement retransmission to PLC, recorder, or SCADA
Operating Conditions & Standards
Power supply: 100–240 Vac/dc or 11–27 Vac/dc. Operating temperature: 0–50 °C; storage: -20–70 °C; humidity: 20–85% RH non-condensing. Documentation references EN 61000-6-2, EN 61000-6-3, EN 61010-1. Model 40TB is listed under UL file E216851 for process control equipment.