Case Studies

MicroLogix 1400 PLC

Allen Bradley MicroLogix PLC LACT Skid Programming

Posted in Allen Bradley PLC, HMI and SCADA, Manufacturing Automation and Intelligence, Oil and Gas Engineering, PLC Programming


DMC programmed the PLC and HMI for a LACT Skid to meet a tight timeline for shipping. The development included custom functionality valves and pumps in the oil, produced water, and fresh water systems. The controller communicated with a Micro Motion Coriolis Transmitter over Modbus to obtain the important flow data.

HMI Programming Easy User Interface

Crude Oil Control Screen

PanelView C600 2711C-T6M

PanelView Component C600 Programming


All skid systems needed reliable controls programming to send signals to the valves and pumps at the appropriate times. The produced and fresh water systems included pressure interlocks to prevent unsafe conditions when improper valves are closed or opened, or when the piping is damaged.

The crude oil system included pressure and flow interlocks similar to the water systems to confirm proper oil flow conditions. This system also required valve control based on the BS&W (Basic Sediment and Water) measurement to either ship or divert the oil and it required valve control to take samples of oil periodically based on the volumetric flow rate. 

DMC configured the PLC as a Modbus RTU Master to read holding registers from the Micro Motion flow transmitter. The PLC also read in the pressure as an analog input to calculate a very accurate volumetric flow rate using the temperature corrected volumetric flow rate from the Coriolis flow meter. The analog input scaling was customizable from the user interface, which was important so that all field device readings could be adjusted easily after shipping the skid.

The skid was going to be duplicated so hardware costs were kept to a minimum, which led to the selection of the MicroLogix PLC and the PanelView Component HMI. The PanelView Component HMIs are very inexpensive compared to PanelView Plus HMIs, and they are programmed differently. DMC programmed the PanelView Component both online using the Ethernet connection and offline using Connected Components Workbench.

DMC provides many engineering solutions for the Oil and Gas Industry.

Customer Benefits

  • Simple-to-use interface for automatic and manual control
  • Advanced user controls to customize settings
  • Low cost controls hardware