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Overview

Lease and dedicated lines have been used to transmit control signals from Elevated Tanks & Reservoirs to the Pump Stations.  These lines are used to transmit signals analog (4-20ma) or digital signals such as  Low Level (LSL),  Hi-Level (LSH), or Pump Run used to control pump operation. These signals may be transmitted over galvanic wire pairs; or as FSK tones over telco voice grade lines.

Replacing Lease and Dedicated Lines with Wireless I/O Telemetry

Over time, these lines may become damaged;  lease line costs increase significantly or become obsolete by the telco.  Radio Telemetry systems  (unlicensed spread spectrum or licensed RF) have been used for many of these applications. Sometimes radio telemetry system cannot be utilized due to terrain obstructions of RF path and/or antenna height limitations due to zoning or esthetic considerations do not allow the use of private RF system.  In these cases. cellular network-based I/O telemetry systems have seen increased use due to the pervasiveness of cellular technology and coverage. In other cases, cellular is not available, or terrain so rugged that cellular coverage is not reliable.  In these case, satellite communications can be used. The SCADALink SatSCADA Platform provides dual mode satellite / cellular communications can be utilized.

  

Plug and Pray – Cellular Based Systems Integration Challenges

With Cellular based I/O Telemetry implementations; Cellular Modems and PLC devices are purchased; The Modem equipment provisioned with the local wireless carrier, and the system configured and tested.

Our experience over the years has shown that this integration approach has often resulted in unanticipated challenges including:

  • Unreliable Cellular Coverage
  • Network Provisioning Issues
  • Network Security Blocking
  • Telco Network Changes Affecting System Operation
  • Equipment Obsolesence

In remote or rural areas cellular coverage may be unavailable or more unreliable than anticipated. In this case, it may be necessary to add antenna height, or in other cases, the system cannot be implemented.

Network provisioning problems and incompatibility between equipment and network operator has sometimes created deployment delays and rework.

In other cases, we have seen telco network security blocking data traffic on the telco network sometime after the initial operation.

In other cases, the cellular network changes have rendered an existing system non-functional requiring field troubleshooting.

Rapid changes in cellular equipment have made support of these custom integrated systems problematic. When the equipment was damaged, there is difficult finding the exact replacement modem. Use of newer or different modems requires additional reconfiguration and retest.  Much wide variety of PLC /RTU and modem equipment allows many ways to address the problem. There is no standard way of implementing and documenting the configuration for future support.

Plug and Play I/O Telemetry with SatSCADA

To overcome many of these challenges,  IO Telemetry Systems can be implemented with the SatSCADA Platform which provides an end to end fit for purpose solution.

I/O Telemetry Systems using SAT1xx Modem/RTU Hardware come complete with managed Cellular and Satellite airtime services.  SatSCADA systems are assembled, provisioned and tested and ready for operation.  For applications in remote areas with unreliable cell coverage, SatSCADA systems with Dual Mode Sat/Cellular Operation provides Satellite connectivity as an alternative link or Cell Satellite fail-over for a critical operation.

Figure 1 shows an I/O Telemetry System implemented using SAT120 with SatSCADA Platform. In this water system application, the requirement was to send a Pump Run Signal for the Tank to the Pump Station. An existing radio-based system became unreliable due to tree growth.  A dual mode satellite/cellular SAT120 based system was implemented perform I/O replication as shown. The SatSCADA Platform provides I/O interconnection via the SatSCADA Server. Connectivity via the SatSCADA platform allows connectivity using the most suitable communications technology at the node.  In this application, cellular coverage was reliable enough to allow use solely of cellular communication at both sites.  A dual mode sat/cellular SAT120 based system allows flexibility to utilize Satellite or Cell at any node. The architecture of SatSCADA I/O Telemetry allows the flexibility of connectivity using any combination of technologies.

Figure 1 – I/O Telemetry using SatSCADA Platform

Wireless I/O Telemetry

 

SatSCADA Platform Adds Web Portal, Trending, and Alarm Notification Function to I/O Telemetry

Some of the added benefits of a SAT1xx based I/O Telemetry System supported by the SatSCADA Platform includes availability of Web Client Access, Alarm/Event History, Trending, and Alarm Notification Capabilities as part of the system. These added features can be beneficial an assist in system maintenance and operations.

SatSCADA Web Client - I/O Telemetry SatSCADA Web Client - I/O Telemetry

Pump Node Web View

The trend shows that the Pump (BLUE) operates for 2 hours every 24 hours.

SatSCADA Web Client - I/O Telemetry   SatSCADA Web Client - I/O Telemetry

 

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