Modbus in Geo SCADA Expert — Configuring Modbus RTU and TCP
Key Takeaway
How to configure Modbus RTU and TCP device connections in Geo SCADA Expert — channel setup, device addressing, point configuration, and register mapping.
Quick Answer
Geo SCADA Expert includes built-in Modbus RTU and TCP drivers. Create a Modbus channel object in ViewX, add device objects with slave addresses, and create point objects linked to specific registers. See also the Geo SCADA Modbus device setup guide.
Modbus RTU Channel
Create in ViewX database. Configure serial port, baud rate, parity, RS-485 mode. Add devices with slave addresses and poll rates.
Modbus TCP Channel
Create with server IP and port 502. No serial port configuration needed. Multiple TCP channels can poll different subnets.
Point Configuration
- Modbus Analog Input → linked to input or holding register
- Modbus Digital Input → linked to coil or discrete input
- Function code selection per point (FC01-FC04)
- Register address (1-based in Geo SCADA)
Data Types
16-bit integer, 32-bit integer, 32-bit float, BCD. Byte order configurable per point.
Examples
Adding a power meter for energy monitoring. Polling a SCADAPack via Modbus from Geo SCADA.
Frequently Asked Questions
Yes. Built-in support without additional modules. Channels, devices, and points follow the same object hierarchy as DNP3.
1-based. The first holding register is entered as address 1, corresponding to register 0 in the protocol frame (40001 in documentation).