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PLC and HMI Programming

We often get asked to integrate our products into some sort of system, this is part of the Services we provide. Here's a project we did a little while ago.

The client wanted to monitor the level of two water tanks on his property and control a remotely operated gate, for this we supplied:

  • Two water level sensors IBP-110
  • A PLC with analog inputs to read the level sensors DEC-005
  • A 6 inch HMI to display the levels and other information
  • Programming for the PLC and HMI
  • A Basic Wiring Diagram for the supplied components
The IBP-110 Level Sensors are designed to be dropped into a water tank, they work by measuring the hydrostatic pressure, which is essentially the weight of the water above the sensor, this is then converted to a 4-20mA signal. These sensors work down to a depth of 10m, we have another version that works down to 20m, the IBP-112, but for this project the tanks were only going to be around 2m deep.

The DEC-005 PLC was chosen over a straight IO module for this system, since it has programmable control as well as 4-20mA inputs to suit the level sensors. Using the Free programming software "ISP Soft" the PLC was programmed to do the following tasks:
  • Read the level sensors and convert the raw readings to depth and volume
  • Operate the gate
  • Monitor the "Gate Fully Open" and "Gate Fully Closed" inputs
  • Trigger an Alarm if the gate took too long to open or close
  • Communicate with the HMI

ISP Soft PLC Programming Software

The HMI supplied included an Ethernet Port which allows the user to view the screens using a standard web browser or control the HMI remotely from a Windows PC application or iOS (iPhone/iPad) App. This is great for a project like this because it allows the gate to be operated remotely and the level of the tanks can be checked from anywhere there is internet access. The HMI was programmed with the following screens:
  • An Overview screen with the two tank levels, a button to operate the gate and status readback from the "Gate Fully Open" and "Gate Fully Closed" sensons
  • A detailed screen for each tank, with levels and tank depth and volume configuration
  • A screen with historic trends for the daily tank levels
  • An IO testing screen to check the IO or quickly operate any devices added to the extra IO in the future

HMI Screens

The Basic Wiring Diagram for the supplied components gave the client an easy reference for wiring the sensors, PLC and HMI all together.

Wiring Diagram

If you have a similar project you need help with or would like a quote for PLC or HMI programming, please Contact Us

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