SCADALink  RIO900 for Tank Level Telemetry

Elevated tanks and reservoirs are used in water systems to gravity feed to distribution.  These tanks or reservoirs are filled by pumping systems which are controlled manually; or automatically by timers or tank level signals. Tank level Telemetry Systems are used to transmit tank level signals to the Pump Station.

Where tank level signals are used, they can be connected from the tank to the pump controls by wire (dedicated or lease line) or wireless means (telemetry). Wireless telemetry systems are used when the tanks and the pumping system are far apart and wired connections are impractical or are not available.

The SCADALink RIO900 provides flexible solutions Tank Level Telemetry as shown in the following diagram.

System Diagram

RIO900 for I/O Signal Telemetry

The SCADALink RIO900 Systems are designed to provide Remote I/O Replication of Analog (4-20 ma) or Digital Signals. I/O Signal Replication using the RIO100 and RIO900  make it easy to interface to both hardwired or PLC  base pump control systems. For Water Systems,  I/O Telemetry can be used for Connecting Tank Level Signals to Pump Control Systems. This I/O Telemetry allows standalone level control independent of the SCADA Communication Network.

The RIO900 Systems can be used in Point to Point Mode for I/O Replication as shown below. I/O Replication may be Analog (4-20ma Level Transmitters) or Digital  (High-Level Flow, Low-Level Switches). While the typical the signal transmission requirement is unidirectional from the tank to the pump station,  RIO900 Systems allow bidirectional signal communications.


The RIO900 System can operate in a Point to Point or Point to Multi-point Mode as shown below.  In point to the multipoint example below,  a tank level signal can be transferred to multiple pump-stations, when multiple pump stations are used to supply the elevated tanks.

RIO900 Connectivity to  SCADA and Modbus Network

SCADA Systems using Modbus Protocol can easily connect to a RIO900 I/O Telemetry Network via RIO900’s RS232 or RS485 Interface as shown in the picture above. This allows connectivity to the RIO900

Network via Modbus Protocol as shown. Connection at of a Modbus Master node at any nodes allows it to access to all  RIO900 nodes configured as Modbus RTU nodes, and to external Modbus Slave RTU or PLC devices connected to RIO900 serial ports.  This feature allows SCADA Host, Modbus Master PLC/RTU, or a Modbus  Level Controller to connect to the Tank RIO900 node.

RIO900 for Solar Powered Systems

RIO900 systems are ideal for Solar Powered Tank Level Telemetry Applications since the RIO900 and I/O feature low power operation including:

  • 24VDC Loop Power Control on Analog I/O Modules.
  • Integral 24VDC DC to DC Converter

Loop Power Control on the SCADALink Analog I/O modules including the AI4 and Combo-I/O has a power saving mode where the instrument power is turned off until a configure Update Cycle The update period can be configured from 1 to 60 seconds with 100ms and 5 second warmup times. With a 60 second update periods, RIO900 based systems can easily be operated with smaller 10 Watt solar systems.  Instrument Power Control can be important when higher power instruments like ultrasonic level transmitters (> 1 Watt) are used, or instances, where there are multiple loop power instruments, are used each drawing 0.5w.

Integral 24VDC DC to DC Power supply in the analog I/O Modules allows 24VDC instruments to be used with 12vdc Solar Power Systems without the addition of external DC to DC Converters.





SCADALink RIO900 systems are ideal for Water Systems applications including:

  • Rural Water Systems
  • Industrial Water Supply Systems
  • Livestock Water Systems
  • Small Water Systems

The SatSCADA/RIO900 is particularly effective for small water systems deployments where there is no existing infrastructure and there are minimal maintenance and engineering staff.







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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