Question 1

What is a weighing transmitter?

Accepted Answer

A weighing transmitter (also called a weight transmitter or weight indicator) converts the analogue millivolt signal from a load cell into a digital weight value, then transmits it over an industrial protocol such as Modbus RTU, RS485, Profinet or EtherNet/IP to a PLC, SCADA system or HMI. It handles calibration, filtering, taring and zero tracking, and typically supports multiple load cells wired in parallel.

Question 2

What is the difference between panel-mount, DIN-rail and stainless transmitters?

Accepted Answer

Panel-mount transmitters drop into a cutout on the front of a control cabinet so the operator can read the weight and use the keypad. DIN-rail transmitters clip onto a 35 mm rail inside the cabinet and have no operator display — the PLC and HMI handle the user interface. Stainless IP65+ transmitters are wash-down rated for food, chemical and outdoor applications where the unit is exposed to water, dust or corrosive agents.

Question 3

Which transmitters are OIML R76 approved for legal-for-trade weighing?

Accepted Answer

The GMT-P1 (panel-mount), GMT-X1 (DIN-rail) and GMT-H2 (stainless wall-mount) are OIML R76 certified, which makes them suitable for legal-for-trade applications in South Africa where SANAS-accredited verification of the scale is required by a third-party verification body. The GMT-X4, GMT-H1 and GMT-H4 are industrial-grade transmitters intended for process control rather than legal-for-trade use.

Question 4

Which industrial protocols are supported?

Accepted Answer

Our weight transmitters support RS232 and RS485 as standard, with options for Modbus RTU, Modbus TCP, Profinet, EtherNet/IP, EtherCAT, CC-Link IE, Profibus DP and CANopen depending on the model. The DIN-rail GMT-X1 also offers Bluetooth setup for fast configuration from a phone or tablet, and the GMT-H1 supports GPRS cellular telemetry for remote silos and tanks.

Question 5

How many load cells can one transmitter handle?

Accepted Answer

A single-channel transmitter (GMT-P1, GMT-X1, GMT-H1, GMT-H2) can drive up to four 350-ohm load cells wired in parallel from one excitation output, which covers most tank, hopper and platform applications. Four-channel transmitters (GMT-X4, GMT-H4) drive four independent scales from one box, which is useful for multi-head fillers, multi-scale check weighers and rail or truck scales with independent corner reads.

Question 6

Do you supply nationwide in South Africa?

Accepted Answer

Yes. R&D Weighing supplies the full General Measure transmitter range across South Africa from our Johannesburg office, with technical and integration support for your PLC, SCADA or HMI. On-site fitting, calibration and commissioning are handled by your installer or system integrator. Spares and same-week replacement units are held in local stock for all six General Measure transmitters listed on this page.