Overview

The client operates a large open cast coal mine, spread over a wide geographic area. Within this mine there are 25 overland conveyors – some as long as six kilometers. There is a control room that monitors and controls all of these conveyors, however, managers lacked the ability to report on maintenance carried out. There is some maintenance that must be completed - all conveyors and protection systems must be tested, by law, monthly. On a single conveyor belt there is a trip switch on either side every hundred meters. In many cases there are in excess of one hundred safety devices that need to be checked to ensure proper functionality.

Initially the client wanted to incorporate the maintenance reporting within their existing automation systems. However, it became clear that the cost to do so made this option difficult to justify. To further complicate matters, there was a mixture of existing systems that control the coal plant, all of which would have to interoperate with the maintenance reporting system.

Approach

The Mango server is housed in the main control room at the coal plant one KM away from the mine. In Mango each conveyor ModBus TCP gateway was added as a ModBus IP data source. The polling was set at two seconds for each device. On each data source, six ModBus registers were added as data points to read key information from each microcontroller, for example: the status of the conveyor belt, which device was tripped, and was it a left or right trip? As some of the ModBus registers on the microcontroller were bit information, meta data points were created using JavaScript to provide statistical information like conveyor availability. Alarms within Mango were set up to alert by email whenever a data source exception was raised after a settimeout. Additionally, event detectors were created to set virtual data points to indicate communication failure on the DGlux HMI. All the created data points were set up in the point hierarchy to ensure a clear data structure within DGlux.

Results

Using Mango allowed the control center to see every device that was being tested. In addition the client can create reports using the data within any chosen time frame. This helped the client to not only operate within the confines of the law, but also from a commercial perspective in that the maintenance supplier was monitored. They saw first-hand that the implementation of Mango was simple, easy and cost effective, especially given the timeframe and scope of the project. Hardware and software choices were easy to make because Mango is compatible with numerous platforms.