The future of test data acquisition
01 August 2016
Electronics testing is a necessary part of many modern manufacturing systems and one that is frequently overlooked in its added value.
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Unlike many mechanical parts, the inspection of electronic components and circuitry is difficult to achieve without actually using them. The internals of a solid state device or multi-layer circuit board may not be visible to the eye and possible defects only detectable through actually using the system. Therefore routine testing is used to ensure that the device will work as expected as failure in service could be anything from irritating to catastrophic.
The huge surge in the manufacturing and application of electronic systems in the products that we use has seen the testing of circuits become big business, and the equipment used to do it is highly valued by the manufacturer. While the physical laws at the heart of electronic devices are generally simple to understand, the performance of a device under an array of conditions becomes more complex. Where there is only the need simply to check the continuity of a circuit and its ability to carry a current – a sanity check that there are no broken components or dry solder joints – then the test equipment can be very basic.
However, in reality we need to satisfy ourselves that components such as switches are working when required, capacitors and resistors are operating within their design envelope, and logic circuits perform as expected under load. Electronics testing is far more complex than the simple determination that a circuit carried a current, and that means the equipment needed to do it must be up to the job.
Whether automated or manually driven by a technician, test equipment will have a number of attached devices, including:
• An ohmmeter to check circuit resistance.
• A voltmeter to determine voltages in the circuit.
• An ammeter to measure the current.
The circuit under test will be stimulated using power supplies and signal generators and may also include signal pattern generators for increased accuracy. Analysis of the outputs could be captured using an oscilloscope or a simple frequency counter. It may be driven by an industrial PC and contain a mass-interconnect device to loop it all together. The intention of this equipment is to check the basic function of the product under test as a viable circuit, but also to ensure that its intended higher functionality is operating as expected. The need for all this equipment makes ATE’s complex, costly, and usually only applicable to high volume production. This means that the customer needs to ensure that what they buy is appropriate to their needs, which is where specialist companies such as Cirris come in.
The design and manufacture of electronic test equipment is highly specialised with the end product being capable of meeting the customers’ requirements. To manufacture that kind of equipment from scratch is a tall order. It requires specialist equipment and usually bespoke software to run it, a detailed knowledge of what the end goal is and how best to achieve it, and of course, experience, time and money. However, most of this can be circumvented by employing a specialist company to use their expertise and specially designed software solutions instead.
The collection of hardware components capable of testing wiring is only half the story and without the capability of automating the process or storing and sharing collected data, it becomes a simple dumb process. However, if the system collects and stores the results in the most time-efficient way, then you have a process that can be shared with those who need the information and need to interrogate the results.
An example of this type of system is the Cirris Easywire system. While many systems can be automated and used to store data for later retrieval, the Easywire system is capable of networking and linking all of the test equipment to one centralised system which can then act as a server that is accessible by anyone with authority to do so. This means that test results can be accessed to get the data that you want at any time from when it was gathered. Easywire has a number of features and functions that help the customer confirm correct operation of products or identify issues in their wiring or electronic components. The main features include:
• The testing of cables, harnesses, components, and electronic assemblies, both at low voltage and high voltage.
• It can be operated by unskilled workers or fully-automated into a production process.
• Share gathered information from multiple test stations through a single network.
• The ability to run several different test modes including, continuous high speed, (to find intermittents), random build, sequential build, and single pass operations.
• Allows the user to create test programs by either importing CAD data or inputting the individual wirelist (pin to pin) criteria.
• Construct and verify new test programs offline, in sandbox mode, to ensure correct operation without interrupting production, then sending it to the test stations.
• Using both visible (written and graphical) as well as audible feedback, the operation of a cable, harness, or circuit is quick and easy to check.
Easywire software runs on a modern entry-level PC and allows the user to collect, analyse, and share the data amongst connected devices. As shown in Figure 1, the Easywire system sits at the centre of the test arrangement with a number of test stations feeding into it and storing test data either locally on a central server, or even in the cloud from where it can be retrieved as required. Additionally, the system is able to flow data both to and from a customer’s site, allowing Cirris to troubleshoot and verify results if and as required. This ability to network and share data is combined with the potential to take in design data and produce test programs – directly from the design, eliminating any possible human error in test program generation.
However, Cirris’ approach is that the customer buys what they need and when they need it, adding systems with the relevant needed capability for the task at hand. All the operating systems on the Cirris Easywire tester range look and feel the same so that the operators on the shop floor have no trouble transitioning from a low cost guided-build tester right up to a high performance CH2 high voltage test systems, despite the increased complexity of the testing being undertaken.
The power of Cirris’ approach lifts the buying rationale from just technical specification against purchase and operating costs to one of how to best equip the business for the future, ensuring maximum efficiency at maximum cost effectiveness.
Provided that systems have the Easywire operating system installed, they can communicate with each other and pass data between them. The advantages of this are that all the test equipment at a customer’s premises can be linked to allow collection of data, downloading of programs, offline editing, calibration data, and other analytical information about process efficiency.
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