Instrumentation • Electronics
memory device. For example, a memory token must be able to be easily inserted and removed by a user wearing arctic gloves in certain military applications. As you can see, while consumer memory products are not
explicitly designed for OEM designs, they do offer unique benefits. However, these benefits may also have unintended consequences. With hundreds of different models of consumer memory
products available, OEMs can’t possibly test, approve and support every device that physically fits. Despite memory manufacturers’ attempts to ensure compatibility, some models will work in an OEM device and others won’t. A lack of control over which devices will work can increase support costs and can be inconvenient for end users. One must also bear in mind that technology standards
change. The transition from SD to SDHC is a recent example. A system designed to use SD cards prior to the release of SDHC will not work with SDHC cards unless the system’s firmware is updated. Likewise, the fast-changing consumer electronics market virtually guarantees that a new technology will emerge in the future, bringing with it new compatibility issues. Finally, using a consumer memory device may increase the
risk of data theft. A misplaced or stolen USB flash drive is not protected from an unauthorised user accessing contained data from a PC, for example. Similarly, using a USB receptacle in an embedded design allows any USB flash drive to plug in, which can increase the risk that information could be pulled off the system or that a virus or other piece of malware could be transferred to the embedded device. Another drawback is that most consumer memory devices
today start at 1GB or higher. As such, embedded systems that require only kilobits or megabits of memory to perform a desired task are essentially paying for capacity they don’t need. While not always apparent in the early stages of the design
process, these considerations should be examined before deciding whether consumer memory meets both the design criteria and the expected use.
Specialist OEM focussed memory
Non-consumer, OEM systems are usually manufactured and designed to last years. As a result, portable memory used in these systems must provide long-term availability and reliability. The environmental conditions in which OEM designs operate can be demanding as well, and there is often an increased emphasis on secure access. Requirements that are unique to OEM designs illustrate why consumer memory devices’ light-duty construction, low cycle life connectors, lack of security features and short product life cycles can be detrimental to non-consumer applications. Rugged construction is another characteristic required by OEM applications, especially for use in harsh environments. Some outdoor applications such as the ones used in the military, construction or agriculture sectors, use portable memory devices to transfer operation and maintenance data between the base and vehicles in the field. The memory device may be exposed to vibration, dirt, moisture, shock, extreme temperature and rough use. Light-duty consumer memory devices and receptacles do not provide sufficient protection or the environmental ratings needed for harsh environments.
Frequent use and long-lasting designs require durable connector systems. Vending machines, for example, may use portable memory to provide cashless vending in non- networked environments. A customer can use the memory device to purchase merchandise from the machine, such as snacks, drinks or even industrial supplies. These machines often see 50-60 cashless transactions per day. Rated at just 1,500 cycles, a USB mating receptacle could wear out in as little as 25-30 days. Furthermore, many OEM applications require increased
security. The widespread availability of devices and systems with USB and SD card interfaces leaves sensitive data vulnerable to data theft and malicious viruses. Accidental data loss and virus uploads have been under the microscope in the Government and commercial sector for some years. In response, some Governments and corporations have banned the use of consumer memory devices to decrease security risks.
Long-term availability for the life of the system is another
key issue to be factored in when choosing memory devices. Consumer memory is driven by the consumer electronics market and therefore subject to short product life cycles and frequent obsolescence. Traffic light controllers are an example of long-lasting OEM designs that need a portable memory solution offering long-term availability. In these applications, technicians use portable memory to upload setup parameters to the controllers. These important pieces of transportation infrastructure are fielded for a decade or more, so a consumer-based memory device would likely become obsolete over the life of the controllers. The inability to meet demands for rugged construction,
a high mating cycle life, secure form factors or long-term availability best illustrate why consumer memory devices should not be used in embedded designs. As a result, OEM portable memory was developed in
response to the unmet needs of many embedded systems. These devices provide the rugged construction, high mating cycle life, secure form factors and long-term availability that average commercial memory products do not deliver. Some manufacturers of portable memory produce
‘industrial’ versions of consumer memory products, such as industrial CompactFlash cards or industrial SD cards. These so-called ‘industrial’ devices may offer an extended temperature range, use slightly more robust materials and support a higher number of write cycles. However, they still share the drawbacks associated with consumer memory devices. They are non-robust, they use low-cycle-life connectors and non-secure form factors; they come hand in hand with potential obsolescence issues and they lack harsh environment ratings.
What is OEM portable memory?
For the purpose of this guide, true OEM portable memory devices are defined as purpose-built systems that provide unique form factors for controlled availability, and baseline physical security. OEM portable memory is most accurately described as a memory system as opposed to a singular device. Another key requirement for a product to truly be
considered to be specialised OEM memory is a unique form factor. This prevents most unauthorised data transfer, helps
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