← All guides

October 23, 2026 · Guide

Export Modbus Poll tags to Voltrus SCADA

When a device works in Modbus Poll, the next step is often to keep it running in a SCADA. Export to SCADA writes a Voltrus SCADA device file with the host, port, unit ID, poll interval, word order and every register. The SCADA imports it on the Modbus devices page by drag and drop, so there is no second round of typing.

Availability. Export to SCADA was added to the Modbus Poll and BACnet Explorer source after Modbus Poll 1.3.5 and BACnet Explorer 1.2.1 were prepared. It is in the open source repository on GitHub and ships with the next app update; if you do not see the button in the app yet, you are on a build from before that update. It needs Pro.

1. Export from Modbus Poll

  1. Add the blocks and connect to confirm the values.
  2. Click Export to SCADA (Pro) and choose Voltrus SCADA device (JSON).
  3. The device name becomes the name of the device in the SCADA. Click Save file.

2. Drop it on the Modbus devices page

In Voltrus SCADA, open Modbus Devices and drag the file onto the table, or click Import file and pick it. The SCADA adds the device with all its registers and tells you what was added or rejected. The device starts polling at once if it is enabled.

What the file contains

{
  "id": "pm5560_meter",
  "name": "PM5560 meter",
  "ip": "192.168.1.50",
  "port": 502,
  "unit_id": 3,
  "interval_ms": 1000,
  "endianness": "big",
  "registers": [
    { "name": "Voltage_3000", "register_area": "holding", "offset": 3000, "register_type": "float32", "scale": 1 }
  ]
}

It is the same JSON the SCADA's own API takes when you add a Modbus device, so you can also post it with a script. Every register carries offset, the 0-based address inside its area, so addresses above 30000 import as they are. Register types are int16, uint16, int32, float32 and float64. Areas are holding, input, coil and discrete.

Limits

  • The SCADA polls Modbus TCP. For an RTU device, put the IP address of a serial gateway into the device after the import.
  • Coils and discrete inputs are written with the uint16 type in their own area.
  • The SCADA limits the number of devices by licence. The import tells you if the limit is reached.

BACnet devices

BACnet Explorer has the same Export to SCADA button in the object browser. Choose Voltrus SCADA device (JSON), then drop the file on the BACnet devices page. The SCADA creates the device and adds each object with its name and present value property.

Voltrus Gateway

Voltrus Gateway is a gRPC service and has no import file. The Voltrus Gateway (JSON) format writes the connect request and the tag addresses in the protobuf JSON mapping, so you can send each part with a tool such as grpcurl or read it from your own client.

Export your Modbus Poll tags to a SCADA

Read the registers you care about in Modbus Poll, then use Export to SCADA in the blocks panel (Pro) to write the tag list for Ignition, Kepware, Node-RED, RustRED, Home Assistant or Voltrus SCADA.

Get Modbus Poll

More guides