• SCADALink RIO100Low-Power Remote I/O RTU Designed for I/O Telemetry and SCADA Applications.


SCADALink RIO100 – Modbus I/O and I/O Telemetry Controller

The SCADALink RIO100 is a flexible I/O controller that can be used for Remote Modbus I/O and I/O Replication.

The SCADALink RIO100 is a controller module that works in conjunction with the SCADALink I/O Modules (DI8,DO8,AI4,AO4, A8D4) to provide Remote Modbus I/O and I/O Telemetry.

The RIO100 used as a Remote Modbus I/O controller can connect up to 10 I/O  modules to add a total of 64 I/O points at a single Modbus RTU address connected via RS232 or RS485.  The RIO100 used in Master-Slave mode along with I/O Modules can be used to perform I/O Replication without the need for additional SCADA Host or Master RTU/PLC System.

The SCADALink RIO100 can be connected to via wired or wireless links. Wireless links include licensed radio networks, spread spectrum radio network, or cellular networks. Knowledge Base for I/O Telemetry Solution

RS232 & RS485 Interfaces

With both RS232 and RS485 interfaces, the RIO100 enables connectivity to field devices without installation of additional interface converters, allowing multiple devices to be multi-dropped on the same COM port. The RIO100 has 2 COM ports. COM1 is RS232 and COM2 is RS232/RS485 wire OR.  Both COM1 and COM2 can be used as the Master Port or Slave Ports

I/O Expansion Module for Up to 64 I/O Points

The RIO100 features an I/O Expansion bus which allows interfacing up to 10 SCADALink I/O Modules including the AI4, AO4, DI8, DO8, A8D4 & COMBO-IO The features may allow additional I/O points for monitoring and control. The I/O Modules can be easily attached to the RIO100 via the I/O bus as shown below:


Modbus I/O

The Modbus RTU Mode can be enabled, and the RIO can be configured with a Modbus RTU address, and connected via RS232 or RS485. With the Modbus I/O Mode, the RIO100 can be used to provide I/O expansion for systems requiring additional modular I/O. The RIO100 is used for I/O for SCADALink SatSCADA Satellite RTU / Alarm Callout Systems.

I/O Telemetry Mode …see more

I/O replication systems are used in applications where a  small number of I/O signals need replicated from one site to another over a remote wired or wireless link. I/O replication can be analog (4-20ma signals) or digital signals (contact closures).

The RIO100 has an I/O Telemetry Mode which allows a RIO100 set in Master Mode to broadcast I/O signals to multiple Slave RIO100. The I/O Telemetry Mode allows I/O replication from Master to Slaves and Vice Versa. This mode has configurable fail safe outputs where I/O defaults to fail safe value on communications fails. The I/O Telemetry mode is easy to configure and allows I/O Telemetry operation or wired (RS232/RS485, wireless modems) and wireless communications (cellular modems, spread spectrum radio modems); or even IP networks.

I/O Replication with the RIO100 is easy to configure, cost-effective, and reliable.

I/O Telemetry for ESD Operation

RIO100 set in Master Mode can  broadcast inputs to multiple Slave RIO100 for ESD shutdowns. The I/O signals will be broadcast to all slaves can be used for ENABLE signals. This signal can be dropped during ESD shutdown. Link failure will also drop the output as well as the LINK failure contact. Analog signals can be broadcast the correspond to speed, flow, or level settings.

Low-Power Operation

With its low-power mode, the RIO100 enables remote I/O  connectivity to intelligent field devices with a minimal solar-power system. For applications with ultra low-power constraints, the RIO100 features a Sleep Mode operation where the RIO100 I/O  is powered down when not in use. This feature is useful when there is multiple 4-20 ma sensors since each sensor can consume up to 0.5 Watt continuous. The RIO turns on for a warmup time on a Modbus request, returns a Modbus RTU response and shuts down after the set off time after last request.




Input / Outputs1 RS232, 1 RS232 / RS485
Serial1200 – 115,200 Baud
Input Voltage+9 to 30VDC
Power Consumption*
Peak Tx Current(@24VDC)105mA
Rx Current (@24VDC)6mA
* – Does not include power consumption of I/O modules
Operating Temperature-40 to 85 Deg. C
RegulatoryFCC, IC , ETSI
Hazardous LocationClass 1 Div 2, Group C, D T3C Suitable for use in: Class 1 Zone 2, IIB, T3






Modbus I/O

Remote Modbus I/O

The RIO100 can be used to provide Modular Remote I/O communicating via Modbus RTU protocol over RS232 and RS485.  A single RIO100 can interface up to 10 SCADALink IO expansion modules (10  total modules – DI8, DO8, AI4, AO4, A8D4, & COMBO-IO) providing up to 64 points of Modbus I/O.

Use as Remote I/O for SAT1xx Family.

The RIO100 can be used to expand the I/O capabilities of the SAT1xx Family using RS485 connectivity. I/O Expansion using the RIO100 allows flexibility to add up to 64 I/O to a SAT1xx System. The RIO100 can be configured in “Power On I/O on Poll”  Mode to conserve power for use in Solar Powered Remote Sites. The Power ON I/O mode only turns on I/O when it is polled. This allows power savings as I/O modules and loop power is turned off when not is use

SCADALink RIO100: Satellite Remote I/O Monitoring and Callouts



Remote  I/O Expansion for Oil and Gas RTU Systems (Class I Div 2)

RIO100 IO Controller and I/O Expansion Modules are Class I Div 2 rated an suitable for use in Oil and Gas Systems.



I/O Replication

SCADALink RIO100 – Modular Telemetry Controller for I/O Replication over Multiple Media

Many Wireless  I/O Replication System incorporate integrated communications  typically a using  proprietary integrated spread spectrum radio. This integrated architecture is suitable for many applications, but may not be suitable for applications where the terrain or application does not allow the use of the proprietary spread spectrum radio technology. The RIO100 with RS232 or RS485 interface can enable integration of any wired or wireless technologies.

SCADALink RIO100 for I/O Replication over RS232/RS485 Interfaces

The SCADALink RIO-100 Modular Controller allows I/O Replication over any RS232 and RS485 link. This allows flexibility for use over the dedicated wire (RS232 and RS485) as well as other communication media including fiber optic,  lease line, cellular, radio-modems, and WAN networks with the suitable interface converters. The RIO-100 interfaces to SCADALink Modular I/O (DI8,DO8,AI4, AO4) – thus allows a flexible number of I/O points from 1 to 64; and simple configuration.


RS485 wiring can be used within a plant or facility. RS485 communications can span distances up to 4000′.

RIO_End to End IO Telemetry

I/O Telemetry over Telco Leased Line (BELL202)

Telco Leased Line was traditionally used for long distant SCADA & Telemetry communications since data could transmit long distances over telco voice grade lines.  Telephone company lease lines were available and allowed telemetry to span long distances using telco lines. Through the use of repeaters extremely long distance leased line networks could be achieved.  Voice circuits could be extended via radio and microwave links to further extend the distance. The increasing costs of leased line have prompted companies to utilize alternative technologies to Lease Lines.

RIO_End to End IO Telemetry-BELL202

I/O Telemetry Using External Wireless Radio Modems

The use of the external modem for I/O Telemetry transmission allows companies the flexibility to utilize existing radio infrastructure networks or equipment. In this example, RIO-100 is used for I/O Telemetry with Transnet 900 Modems.

RIO_End to End IO Telemetry-External Radio Modems

Benefits of I/O Replication over Existing Radio Channels

RIO100 allows I/O Telemetry over existing radio channels. The RIO-100 allows operation over existing serial links with ability to operate on a multiplexed basis with serial SCADA traffic.  I/O replication over existing radio works can be useful to minimize the need to install additional radio antennas and feedlines and minimize potential RF interference of additional co-located radio systems.

The RIO100’s ability to interface to any external radio modem allows the flexibility for I/O Replication using all RF bands. RIO100 in I/O Replication Mode incorporates fail-safe configuration where I/O goes to a default condition upon link failure.

Telemetry over Cellular

The following diagram shows I/O Telemetry over Cellular IP network by configuring the modems are configured in a virtual serial connection.

RIO_End to End IO Telemetry-Wireless

Benefits of  I/O Replication over Cellular Links  

I/O replication over cellular networks can overcome terrain obstructions minimize the need for large antenna structures. In urban and suburban installations, antenna structures height will be limited due to esthetic requirements and clearance requirements.

I/O Replication over cellular can be configured for both points to point in a point to multipoint architecture. The point to the multipoint application is often required for water reservoir control in water supply systems.

I/O Telemetry over IP Networks

With the pervasiveness of IP networking; I/O Telemetry can be operated over Wireless, DSL, and Fiber based IP networks, private or public.  With IP connectivity, I/O Telemetry can span great distances using IP infrastructure.

Telemetry over Fiber Links

Fiber Optic modems can be used to provide isolated I/O Telemetry directly over a point to point serial link or alternatively IP communications can be used over fiber optic networks.

Use of I/O Replication and Broadcast Shutdown

I/O replication systems are used in applications where a  small number of I/O points need to be transmitted from one end to another. In these cases, I/O replication is easier and more cost effective to configure, and more reliable.

The RIO100 allows flexibility for I/O Replication – operating in a point to point, point to multipoint; and broadcast mode. Broadcast mode is used for shutdown.




SCADALink RIO100-ESD: Remote I/O RTU with Emergency Shutdown

The SCADALink RIO100-ESD is a specialized RTU designed for emergency shutdown of Oil and Gas pumping systems such as:

  • Well Production into Tank Batteries
  • Pumping into Disposal and Injection Wells
  • Source Well Pumping
  • Source Water for Fracking Operations

Based on the RIO100, the SCADALink RIO100-ESD is a remote RTU preconfigured for emergency shutdown applications. The SCADALink RIO100-ESD integrates with existing radio networks to broadcast shutdown signals to multiple remote sites while simultaneously providing wireless access to field data over Modbus RTU protocol. With the I/O module attachment, the SCADALink RIO100-ESD broadcasts the status of the I/O module through the existing radio network, causing a shutdown at remote sites to prevent emergency situations. The RIO100-ESD is simple to use with no programming required to set up the emergency shutdown functionality.


  • Secure factory configured network
  • Failsafe operation with configurable time-out
  • 2 serial interfaces (1 RS232 and 1 RS485 serial)
  • Standard modem support
  • Failsafe ESD I/O modules
  • Interoperation with existing SCADA traffic
  • Modbus RTU protocol


The SCADALink RIO100-ESD system consists of a Master RIO100-ESD communicating to multiple Slave RIO100-ESD over a multi-drop network. The RIO100-ESD uses a secure broadcast protocol for ESD I/O control. ESD inputs at the Master RTU are broadcast to matching ESD outputs at the Slave RTUs. ESD functionality is preconfigured and no programming is required.

SCADALink RIO100: Emergency Shutdown for Existing Networks

 RIO ESD- Emergency Shutdown for Existing Networks

Plug-and-Play Operation

Using the RIO100-ESD system for an ESD System, the RIO100-ESD Master is be connected to a Master radio modem of multi-drop network and the RIO100-ESD Slaves are connected to the Slave radio modems on the same network. Outputs at the ESD I/O on the Slave will match the input state at the ESD I/O Master. If data link or Master RIO100-ESD fails, the Slave RTU outputs will go into failsafe / “OFF” state. Note that for ESD operation, no SCADA Host or PLC master equipment programming / configuration is required. In this manner, a wireless ESD system can be rapidly and securely implemented. Point-to-multipoint polling can be integrated in the future.

Fail Safe Operation

The RIO100-ESD features failsafe operation. ESD outputs will shut down if there no communication from the master to slave exceeds the time-out configured in the Master (10-60 seconds).

Standard Modem Support

The RIO100-ESD can operate with industry standard licensed and unlicensed radio modems and wireline modems including:

  • Microwave Data Systems (MDS) – 4710, SD2, SD4, SD9, Transnet 900, INET2-900
  • FreeWave FGR2, FGR4 & FGR9 Series Radios
  • BEL202 Wireline Modems

Communication to modems from the RIO100-ESD can be configured for RS232 or RS485. RIO100-ESD can be implemented on any SCADA communications network that provides a point-to-multipoint broadcast mode. This includes IP type radios that have a point-to-multipoint compatibility mode (MDS SDx, INET2 900) or IP radio modems that have a point to multipoint emulation (UDP / TCP multicast) mode.

Inter-Operation with SCADA Data Traffic

The RIO100-ESD Master coordinates ESD protocol data with SCADA data, allowing standard SCADA data to inter-operate with RIO100-ESD traffic data.

Modbus RTU Protocol

The RIO100-ESD Slave I/O Points can be polled by standard SCADA Host or RTU Masters via Modbus RTU protocol if the RIO100-ESD RTU mode is enabled and a Modbus RTU address assigned.Note: For ESD operation only, Modbus Protocol is not required or utilized.

I/O Modules

The RIO100-ESD can interface with up to 8 SCADALink I/O Modules to provide expanded I/O functionality.

RIO900-ESD with Integrated 900 MHz Unlicensed Radio

The SCADALink RIO900-ESD model with integrated 900 MHz Spread Spectrum Radios can be selected if the customer requires solution with integrated radio modem: RIO900-esd

SAT100 Master for Remote ESD Callout and Control for RIO100 Networks

A SCADALink SAT100 can be integrated with the RIO100-ESD system to provide remote ESD monitoring and alarm callout. A SAT100 can be used as a data concentrator at the Master RIO100-ESD site (eg. Tank Battery). In this configuration, the user can remotely monitor the status of all sites including the master site and remotely initiate a shutdown.

Point to Multipoint (PMP)

Sometimes there is a requirement not only for Point to Point to Point but also Point to Multipoint Bidirectional Telemetry. PMP I/O telemetry systems are shown below. Inputs (1) are broadcast to Outputs (1), Analog Inputs (2) are replicated as Analog Outputs (2), Digital Inputs (3) are replicated as Digital Outputs(3).

 End to End IO Telemetry - Point to Point or Point to Multipoint


  • Well Production into Tank Batteries
  • Pumping into Disposal and Injection Wells
  • Source Well Pumping
  • Source Water for Fracking Operations




1. RIO900
ItemPart No.DescriptionNote
License Free 900 Mhz Wireless Modem, I/O, and RTU for I/O Telemetry and SCADA Applications.
2. Expansion Modules
ItemPart No.DescriptionNote
4 Analog Inputs (4-20mA)
4 Analog Outputs (4-20mA)
8 Digital Inputs
8 Digital Outputs (Relays)
1 Analog Input (4-20ma) / 1 Analog Output (4-20ma) / 2 Digital Inputs / 2 Digital Outputs
ESD Modules
1 Analog Input (4-20ma) / 2 Digital Inputs
1 Analog Output (4-20ma) / 2 Digital Outputs
2 Digital Inputs.
2 Digital Outputs.
3. Packaging Options
ItemPart No.DescriptionNote
3AAC Powered PackageAC Powered Package without battery backup.B
3BAC Powered Package with Battery BackupAC Powered Packages with battery backup.B
3CSolar Powered PackagesSolar Powered Packages with NEMA4 EnclosuresB


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