The Hindu Business Line : When speed matters...

Instead of upgrading to a faster computer processor, you may consider investing in a faster data acquisition device (DAQ) that can not only process your jobs faster but also control your computer.

A DAQ resembles a computer chip and is housed inside a computer. It gathers signals from measurement sources and digitises them for storage, analysis and presentation on a personal computer (PC). DAQs can control processes such as temperature and pressure control with accuracy and speeds ranging from 10,000 samples a second to 10 lakh samples a second."Using a DAQ has resulted in reducing development time by up to 70 per cent," says Arun Venkataswamy, Technical Director, Pyramid Precision Engineering India Ltd. Pyramid constructs test machines for the automotive industry. These include brake test systems, steering wheel test systems and tyre test systems.

Before a DAQ was used, electronic circuits were designed manually and turnaround time for large projects, such as a railways project, would take months, says Venkataswamy.

National Instruments makes DAQs and recently introduced a USB-based high speed DAQ called CompactDAQ. DAQs come in many forms depending on their point of contact with a PC — USB port, PCI, Firewire and parallel or serial ports.

Pyramid uses 10 USB DAQs (for mobile systems) and 15 PCI DAQs (for lab based systems) for its operations. A DAQ can be integrated with another device called the Proportional integrable and derivative (PID) controller so as to control a PC.

With DAQs, it is simple to design a test machine, says Venkataswamy. The customer specifies requirements that can be designed physically using software called LabVIEW. LabVIEW comes along with the DAQ and programmes the DAQ based on the mechanical and electrical specifications.

Post programming, inputs and outputs for the test are chosen and plugged to the PC. The test machine is ready.

But test machine designs are often changed (on request by customers) to accommodate as many functions as possible. "Conventionally, it was very difficult and costly to make these changes," says Venkataswamy. This was partly due to the unfamiliar C/C++ programming used to design the test machines.

With LabVIEW, that problem has been eliminated. Not only can different functions be added, but one can also easily programme the DAQ. "Even freshers can pick up programming on LabVIEW. So our dependence on highly skilled software engineers is reduced. We can rely on our mechanical engineers themselves for programming," he says.

Another advantage of the DAQ is its decision-making capability. The DAQ can generate automated reports (up to 10 pages long) from the data it has collected and analyse the same. Such reports help in monitoring product performance.

With diverse functionality, the DAQ can control multiple computers. It can be applied in the area of virtual instrumentation. (The global virtual instrumentation market, worth about $48 billion, encompasses testing, measurement and automation, which require DAQs.)

The DAQ can segregate internal computer processes and make it seem like dedicated DAQs are controlling processes. "More than functionality, the speed advantage will make the DAQ popular in future," says Venkataswamy.

archana@thehindu.co.in