Amplicon were recently asked to provide a solution that would test mass flow computers being made by an instrumentation manufacturer for the oil and gas industry. The brief was to replace an aging collection of purpose built and manual test equipment, with an automated system that could reduce costs and increase productivity by simultaneously testing 16 flow computers. The solution had to be a modular expandable system using Commercial Off The Shelf (COTS) products, and a real-time operating system able to handle simultaneous inputs and outputs.
The mass of the gasses and liquids are affected by changing temperature and pressure, therefore a flow computer is required to calculate the mass flow rate of a fluid. The flow computer takes readings from volumetric flow meters, temperature and pressure sensors.
The flow computers have sixteen 4-20mA input signals (for pressure, flow and temperature measurements), RS485 Modbus communications and twelve alarm relays.
The ATE (Automatic Test Equipment) has to be able to generate 4-20mA signals and read the status of the relays on up to 16 flow computers at the same time. This equates to 256 analog outputs and 196 digital inputs.
Although a Windows based system could potentially control all the outputs and inputs, it would struggle to manage all the operations effectively
Therefore a real-time system was offered based on a DAP (Data Acquisition Processor). This data acquisition card uses an on-board microprocessor and its own operating system to manage hundreds of input and output channels. “Pipes” are used for data to flow through the DAP architecture, independently from each other and the PC’s operating system. This allows up to 512 analogue inputs, 128 analogue outputs and over 1000 digital channels to be controlled from one DAP card in real-time.
This system comprised of two DAP cards installed in an Amplicon Industrial PC, plus 32 eight channel analogue output cards and 12 digital input cards installed in two further 19” rackmount enclosures. They were fitted into a 19” rack along with a rackmount monitor and keyboard and a rackmount oscilloscope for additional testing.
This powerful yet modular design provided a flexible solution, able to control many channels in real-time, and easy to maintain in the long term. It also complied with the desired COTS (Commercial Off The Shelf) product requirement that enabled the customer to see a saving of over £100,000 compared to the cost of developing an in-house system.
Amplicon’s expertise in industrial computing combined with 25 years experience in the data acquisition market provides a unique position from which to offer completely customised and cost-effective test systems. The DAP range of products provides a unique platform on which to build the most complex of Automatic Test Systems.