Wiress IO

SCADALink RIO900 Wireless I/O Telemetry Radio

The SCADALink RIO900 is designed to operate as Wireless IO, Wireless RTU, and Wireless  Modem System.

License Free 900 Mhz Wireless Point-to-Multipoint Communication

The RIO900 features license-free 900 MHz spread-spectrum radio technology providing a range of up to 20 miles.  Longer range can be achieved with RIO900 nodes configured as Repeaters.

SCADALink RIO900 Wireless I/O Point to Multipoint Communications

Wireless IO

Wireless I/O Telemetry

A key integral feature of the RIO900 is its wireless I/O signal replication mode (Figure 1).  In this mode, OUTPUT modules are paired to INPUT modules set at the same module address. The RIO900 supports replication of Digital I/O (contact closures) and Analog  I/O (4-20 ma) using AI/AO,  DI/DO, or COMBO-IO Pairs. The RIO900 supports both point to point and point to multi-point I/O replication.

Figure 1
Wireless IO

RS232 & RS485 Interfaces

With both RS232 and RS485 interfaces, the RIO900 allows connectivity to field devices without additional interface converters, allowing multiple devices to be multi-dropped on the same COM port.

SCADALink RIO900: RS485 Multidrop

Wireless IO

SCADALink RIO900: RS485 and RS232

Wireless IO

Modular I/O Expansion

The RIO900 has an I/O Expansion bus which allows interfacing up to 10 SCADALink I/O Modules including the AI4, AO4, DI8, DO8, A8D4, COMBO-IO, DI-ESD, and DO-ESD.  The I/O Modules are bussed to the RIO900 via the I/O bus as shown below. Modular  I/O expansion allows compact addition of remote I/O.

Wireless IO

Modbus RTU Mode

Each RIO900 can be configured with a Modbus RTU address and polled by a Modbus Master via Modbus RTU protocol. The Modbus Master can be connected at any RIO900 node on the network as the RIO900 RF Platform is a peer to peer network.

Low-Power Operation

The RIO900 is designed for Low Power Operation. The RIO900 enables SCADA communications to intelligent field devices with a minimal solar-power system. With current draw of < 0.5W (20 ma at 24VDC and 40 ma at 12VDC) in RX mode the RIO900 has some of lowest power draws for SCADA radios. The RIO900 combined with low power I/O and I/O sleep modes, the RIO900 Platform features the lowest power Wireless RTU and I/O Telemetry Systems available.

For applications with ultra low-power constraints, the RIO900 features a I/O Sleep Mode operation where I/O modules and 24VDC Loop power is powered down when not in use to be awakened by serial communication. In addition the analog I/O modules have a periodic update mode which turns of the loop power when is off the update interval.

Store and Forward Repeater Mode

Any RIO900 Node can be configured to operate as a Store and Forward Repeater Nodes.   Sites that do not have a Line of Site Path may be connected via a Stand Alone Repeater site or via another RIO900 Node.

Stand-Alone Repeater

RIO900 Platform Features

  • Secure configurable encrypted network
  • Failsafe operation with configurable time-out
  • 2 serial interfaces (1 RS232 and 1 RS485 serial)
  • Integrated 900 MHz Radio
  • Failsafe ESD I/O modules
  • Inter-Operation with existing SCADA traffic

I/O Telemetry

Wireless I/O Telemetry

The RIO900 is designed specially to handle situations where I/O needs to be replicated from on site to another (Figure 1). The RIO900 System can handle both points to point  or point to multi-point configurations.

Figure 1 – Point to Point I/O TelemetryWireless IO

Figure 2 – Point to Multipoint I/O Telemetry

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 is 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).

Wireless IO

Virtual I/O Mode

An RIO900 can be configured for Virtual I/O Mode where Modbus Registers of the RIO900 are mapped to I/O values of Virtual Output Modules as shown in Figure 3.  In this mode Remote I/O is mapped to predefined Modbus Register space in the target. This enables Modbus Masters such as an RTU/PLC Master or SCADA Master to use I/O points from an RIO900 based I/O telemetry System without connecting to actual I/O (Figure 3) . This saves on wiring and I/O hardware costs.

Figure 2 

Wireless IO

Figure 3 – Virtual I/O

Wireless IO

Shutdown Systems:

RIO900 for Wireless Shutdown Systems



RIO900 and COMBO-I/O Modules are used Water System I/O Telemetry.

Combo I/O Modules are coded 1, 2, or 3.

AI – Level (LT)
DI1 – Level Switch High (LSH)
Di2 – Level Switch Low (LT)
AI – Level (LT)
DI – Pump Run Status
DO – Pump Run Command



RIO900 and COMBO-I/O for Wireless 4-20ma Transmission

A pair of SCADALink RIO900 and SCADALink COMBO-I/O modules are recommended for applications formerly using SCADALink SR900T Transmitter and SR900R Receivers.

A pair of SCADALink RIO900 and COMBO I/O pair are symmetrical with  1 AI (4-20ma), 1 AO (4-20ma), 2 DI, and 2 DO, thus making equipment sparing easier. The extra bidirectional I/O of the COMBO-I/O make this system more flexible and future proof compared to SR900T and SR900R pairs. In additional the RIO900’s modular I/O and serial communication ability give it additional flexibility for system upgrades compared to SR900T/R pairs.


Wireless RS485

RIO900 for Wireless RS232/RS485 Extension

In addition to IO Telemetry Mode,  the RIO900 has RS232/RS485 Serial Communication where RS232 and RS485 serial ports in an RIO900 network appear as a multi-drop serial network.  In the RIO900 System, I/O Telemetry and serial communication can operate simultaneously. Figure 1 shows systems where serial communications can operate simultaneously as I/O Telemetry.

Figure 1

Wireless IO


 Mounting 30.5mm DIN Rail
 Dimensions 114.5mm (H) x 22.6mm (W) x 99mm (L)
 Radio Communications
 Band 902-928 MHz LicenseFree
 Spread Spectrum (North America)
 915-928 MHz (Intl version)
 Tx Power 100 mW – 1 Watt
 Rx Sensitivity -103 dBm @Hight / -106@Low
 RF Data Rate 110 or 250 Kbps
 Range (LOS) >20 miles
 Antenna Connector MCX
 Input / Outputs 1 RS232, 1 RS232 / RS485
 Serial 1200 – 115,200 Baud
 Input Voltage 10 to 30VDC
 Power Consumption*
 Peak Tx Current 86 mA @24V / 175 mA @12V
 Rx Current 20 mA @24V / 40mA @12V
 Operating Mode
 * – Does not include power consumption of I/O modules
 Operating Temperature -40 to +70°C
 Regulatory FCC,  IC, ETSI
 Hazardous Location Class 1 Div 2, Group C, D T3C
 Suitable for use in: Class 1 Zone 2, IIB, T3



The RIO900 GUI is a windows-based application used to configure, save and restore all RIO family device settings. It is connected to the RIO device via serial cable to COM port.


The RIO900 can be configured for wireless data communication operation.





SCADALink RIO900 Wireless I/O Telemetry Radio Ordering Information

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. Omni Antenna Kit (Used with Master in Point to Multipoint Systems)
ItemPart No.DescriptionNote
3AOmni Antenna
Omni Antenna (N Female Connector) and Mounting Bracket
3BAntenna Cable35' LMR400 c/w N-Male ConnectorA
3CAntenna Lightning Arrester6GHz, N-F Connector , Bi-directional protection
3DAntenna JumperMCX to N-Male Jumper - 3'
4. YAGI Antenna Kit
ItemPart No.DescriptionNote
4AYAGI Antenna6dB YAGI Antenna c/w N-Female connector
4BAntenna Cable35' LMR400 c/w N-Male ConnectorA
4CAntenna Lightning Arrester6GHz, N-F Connector , Bi-directional protection
4DAntenna JumperN-Male to MCX Male 3'
5. Antenna Options
ItemPart No.DescriptionNote
5AANT-900UHF, 902-928 MHz, 3dBi, N (F) Connector.
6. Packaging Options
ItemPart No.DescriptionNote
6ARIO900 Telemetry System PackageA complete package with NEMA4 Enclosures, Solar Power, 24VDC Loop Power, Class I DIv 2 Certification and Industry Sensor Sourcing.

6BAC Powered PackageAC Powered Package without battery backup.B
6CAC Powered Package with Battery BackupAC Powered Packages with battery backup.B
6DSolar Powered PackagesSolar Powered Packages with NEMA4 EnclosuresB


  1. Standard Cable Length – Order Longer Lengths as Required
  2. Packaged Systems Available – CSA Class I Div 2 or CSA General Certification

Connection Example


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