GMT-P1 Weight Transmitter
Quick specs
| Approval & Accuracy | |
|---|---|
| Approval | OIML R76 |
| Excitation Voltage | DC 5 V, 200 mA (max); 1 analog load-cell input (0 – 15 mV) |
| Signal Input Range | 0.00 – 15 mV (3 mV/V load cell) |
| Connectivity | |
| Digital I/O | 1 input, 2 outputs; 4 set points |
| Serial Comms | RS232 or RS485 |
| Analog Output | Analogue output |
| Physical & Environment | |
| Housing | Compact panel-mount |
| IP Rating | Front panel-mount inside enclosure |
| Mount | Panel cutout 93 × 46 mm |
| Power Supply | DC 24 V ±5%; ~10 W |
| Operating Temperature | -10 ℃ to +40 ℃ |
| Operating Humidity | ≤90% RH, non-condensing |
Applications
Applications
- Hopper weighing
- Tank and silo level
- Batch dosing panels
- Concrete and bitumen mixing
- Metallurgy furnaces
- Chemical industry feed lines
- Replacement for legacy panel indicators
OEM & ODM ready
Built for integration into your line, your machine, or your brand.
As General Measure’s South African partner, R&D Weighing supports OEM and ODM engagements across the transmitter range. From private-label badging through to custom enclosures, communication protocols, and full system integration with your existing PLC, MES, or ERP environment.
- Private-label finishing & branding
- Custom enclosure & mounting options
- PLC / MES / ERP integration
- Bespoke communication / protocol configurations
- Multi-channel synchronisation
- Engineering support throughout commissioning
Compliance & quality
CE compliant
IP65 rated
The GMT-P1 weight transmitter is a compact 105 × 57 mm panel-mount weight indicator built for control panels where a full-size indicator will not fit. With RS232 or RS485 serial communication, four set points, 1-input / 2-output digital I/O and an optional analogue retransmission board, the GMT-P1 is the budget-friendly workhorse for hopper scales, batching panels, process weighing stations and as a drop-in replacement for older indicators in concrete plants, feed mills and metallurgy lines across South Africa.
Why the GMT-P1 suits compact panels
Most legacy industrial weight indicators take up a full DIN 96 × 96 or larger cutout on a control panel. The GMT-P1 reverses this: a 93 × 46 mm cutout and only 57 mm of depth behind the panel face mean it fits inside narrow operator stations, electrical sub-panels and machine-mounted enclosures that simply have no room for a bigger indicator. The 6-digit LED display stays bright and readable in dusty plant rooms, and four front-panel keys handle zero, tare, mode and entry without an external HMI.
For sites running 24/7 - feed mills, cement batching, beverage filling and metallurgy furnaces - the GMT-P1 gives line operators the readout they need at the panel face while the load cells, junction box and wiring stay sealed inside the enclosure.
Communication and set-point control
The GMT-P1 ships with RS232 or RS485. That covers virtually every legacy serial PLC, weighing-software package and bench-top printer still in service in South African plants, so a P1 will talk to existing equipment without protocol adapters.
The four built-in set points drive batching and dosing logic directly via the 2 open-collector outputs, with the single digital input handling remote zero, tare or print triggers. For sites moving to 4 – 20 mA loops or 0 – 10 V analogue retransmission, the optional analogue output expansion board adds that capability without a redesign of the panel.
When to choose the GMT-P1 over a larger transmitter
Choose the GMT-P1 when panel space is the constraint, when a simple operator interface beats a full HMI screen, and when the application needs no more than one load-cell channel and four set points. It is also the obvious pick when retrofitting older devices-compatible installations - the P1 speaks those legacy protocols natively and runs on the same DC 24 V power supply most existing weighing panels already provide.
For larger control rooms with PLC-based automation, or for sites that need Ethernet/IP, Profinet or EtherCAT, the DIN-rail GMT-X1 is usually the better fit. For washdown and stainless environments, look at the GMT-H2 wall-mount instead.
Frequently asked questions
What is the panel cutout size for the GMT-P1?
The GMT-P1 fits a 93 × 46 mm panel cutout. The front bezel measures 105 × 57 mm and the unit only protrudes about 57 mm behind the panel, so it suits shallow operator stations and machine-mounted enclosures.
Does the GMT-P1 support Modbus?
Yes. The GMT-P1 supports Modbus RTU over RS232 or RS485. Ethernet-based Modbus TCP is also available on the P1.
Can the GMT-P1 drive batching outputs directly?
Yes. The GMT-P1 has two open-collector outputs that can drive contactors, solenoids or PLC inputs directly. For a simple two-speed dosing loop (coarse + fine) or fill-to-cutoff, the P1 handles the control logic without needing an external PLC.
What power supply does the GMT-P1 need?
The GMT-P1 runs on DC 24 V ±5% (about 10 W). Most existing weighing panels already provide a 24 VDC , so the P1 wires straight in without additional supplies.
How many load cells can I connect?
The GMT-P1 has one analog load-cell input that accepts a 6-wire (preferred) or 4-wire connection from a parallel-summed junction box. It works with 1 mV/V, 2 mV/V and 3 mV/V load cells from any manufacturer.
Is the GMT-P1 OIML certified?
The GMT-P1 is built to the same metrological performance as the rest of the range - 0.01% F.S non-linearity, 1/1,000,000 maximum display accuracy and 10 PPM/℃ gain drift. It is positioned as a process and industrial transmitter rather than a legal-for-trade indicator; if you need OIML / SANAS verification for a specific application, contact us before ordering.
