Setting Up Reliable Monitoring for a Water and Wastewater System Using Phoenix Contact Radioline

Blog Post by Patti Engineering Senior Engineer Nick Hitchcock, P.E

Recently, we worked on a project to monitor and control equipment over distances.  In our case, we were controlling and monitoring water wells spread throughout a city. Originally, the wells were all hardwired back to the water plant. This became a problem when buried wires became damaged by digging or by other utility workers unknowingly disconnecting lines.  Also, the telephone lines were leased in places, causing a monthly expense.

We turned to 900MHz radios.  We installed radio based I/O modules at each well head and the water plant using Phoenix Contact Radioline.

Radioline Distances

There are 3 modes of operation for Phoenix Contact Radioline:

  • Wire-In –Wire-Out: maps I/O from one location to another via wireless without the need for an additional controller or software
  • Wireless I/O to Modbus: collects I/O directly at the Radioline wireless module using extension modules. This I/O is addressed via Modbus without the need for additional hardware
  • Wireless Serial: provides RS-232 and RS-485 networking, connecting serial end devices, PLCs and RTUs reliably

We used the Modbus mode and read the I/O into our PLC.  Using the Modbus mode basically turned them into a remote I/O rack sitting on a Modbus network.

Things to keep in mind with radios

Virtual Survey
  • Perform surveys to verify that the radios will work in your situation. You’ll need to make sure that the required distances have been met.  We did two types of surveys.
    • Virtual surveys using software – Phoenix has software that can help with this. We also used publicly available land surveys.
    • Physical survey – Buildings, trees, and other obstructions aren’t always modeled into the software. We took the equipment into the field to verify our virtual findings.
  • 900MHz is suitable for non-line-of-sight applications, but that does reduce distances.

By switching to this system, the municipality now has a much more reliable monitoring system for their water and wastewater.

Related categories: Blog Control Systems Integration

Nick Hitchcock's Bio

Texas Director of Operations

Hired in 2008, Nick Hitchcock has served in several engineering and management roles in the company’s Austin office. Starting out at the Michigan office, and moving to Texas in July 2010, he now serves as the Director of Texas Operations.