Application
HVAC and refrigeration
An all-in-one body with eight PT100 inputs, and a 4G panel so the service team sees the alarm before the building manager does.
The machine
Chillers, air handling units and heat pumps
An air handling unit is a temperature loop, a humidity loop, a damper, a fan and a valve, in a metal box on a roof. A chiller adds compressor staging and a condenser. Neither is fast, and neither is where a control engineer wants to spend a week.
What matters is the enclosure count and the service call. A rooftop unit with a panel, a controller and a separate temperature module is three boxes to wire, seal and label; an all-in-one body is one cut-out.
The control
What has to happen, and fast enough
The GT all-in-one pairs a 7-inch panel with 16 digital inputs, 16 transistor outputs and eight PT100/NI120 inputs in one body at DC 24 V. The control logic, the HMI and the sensor conditioning share one power supply and one enclosure.
For remote sites, an IoT HMI with a 4G module pushes alarms to the service team and allows a VNC session without a site visit. Modbus TCP on the panel's Ethernet port hands the unit's status to the building management system.
Recommended hardware
A typical bill of materials for this machine
These are the models the export desk quotes most often for this application — not the only valid combination.
| Function | Recommended | Why |
|---|---|---|
| Operator panel | GT-070-32MT-8PT | 7-inch panel + controller + 8 PT100 inputs in one body |
| Remote option | SK-070QS-G | IoT panel with 4G module for unmanned sites |
| Valves and dampers | S-E4AI2AO | Four analogue inputs and two outputs, 16-bit |
| Compressor staging | Built-in relay or transistor outputs | GT-070-30MR for relay loads |
I/O counts and axis counts assume a mid-range machine. Send the actual list and the quotation will be sized against it.
Engineering notes
What usually goes wrong
- For rooftop and plant-room units, the all-in-one removes a power supply and a serial cable from the BOM and from the commissioning checklist.
- Push the alarm rather than waiting for a call: an IoT panel with a 4G module reports a high-pressure trip before the building manager notices the temperature.
- Keep BMS traffic on Modbus TCP and the service traffic on the cloud module; mixing them on one link makes both harder to diagnose.
- Specify PT100 rather than thermistor where the sensor cable runs more than a few metres.
Send the machine, not the model
Describe the axes, the I/O and the market it ships to. We answer with a model code, a cut-out check and a landed-cost quote — usually within one business day.
Next step
Tell us what the machine has to do.
Send the axis count, the I/O list or a photo of the existing panel. You get a model recommendation, a wiring note and a quote — usually within one business day.