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Modbus I/O for 12 VDC Powered Systems


The SCADALink RIO100 Modbus I/O Controller and Analog I/O Expansion Modules can be used to provide stable high resolution I/O expansion for smaller RTU and Controller equipment and for control system operating on 12 VDC power systems.

I/O Expansion for Small RTU and Flow Computer Systems

Existing small RTU and EFM systems often do not have adequate integral I/O and sometimes require additional I/O expansion. The SCADAlink RIO100 Modbus I/O Controller can be used with I/O expansion modules to expand these RTU or EFM system I/O with up to 64 additional I/O points. Modular I/O Expansion include 4 Point 4-20ma Input (AI4), 4 Point Digital Input (DI8), 8 Point Digital Output (DO8), 4 Point 4-20ma Analog Output (AO4); and Combo I/O (1 AI, 1 AO, 2 DI, 2 DO).

A common application for Modbus I/O expansion to add casing and tubing pressure measurements to a EFM system on a gas production well.

The RIO100 system can be connected to RTU/EFM systems via RS232 or RS485 connections.

24 VDC Loop Power for 12VDC Powered Systems

The SCADALink AI4 and COMBO-I/O I/O Expansion Modules have integral 24VDC DC to DC Converters that generate 24 VDC Loop Power from a 10-30 VDC Supply Voltage. This allows provides stable 24VDC loop power for 4-20ma instrumentation operating on 12 VDC systems.  Frequently analog input channels do not operate reliably on 12 VDC power systems due to noisy power supply or inadequate 4-20ma loop voltage.

Isolated 4-20ma Inputs

SCADALink RIO100 Modbus I/O Expansion can be useful in applications where grounding issues can cause inaccurate or problematic analog input channels for PLC/RTU Controller with no-isolated analog inputs.