Universal Serial Bus (USB) ports have become very popular and most new computers come installed with two or more. Users are comfortable with the advantages of USB’s plug and play and with the variety of peripheral devices that can be easily connected. However, there are still many legacy devices, especially in industrial automation environments, where RS232 (and RS422 / RS485) serial connectivity works just fine. It is for these devices that USB to RS232 converters are ideally suited.
Here are five important features to look out for before choosing a supplier’s USB converter product.
Feature #1: Support for Microsoft Vista and Windows 7 Operating systems.
Although most manufacturers supply drivers for earlier Microsoft system software, as well as for Apple Mac and Linux, there have been performance issues with some manufacturers’ converter products and Microsoft’s newer releases that show up as screen freezes, crashes and connectivity problems.
Solution: Check that the converter comes with drivers that have been optimized for these two Microsoft offerings. (For more detailed information search online for info on Microsoft’s “Windows Hardware Quality Lab” (WHQL) and “Virtual Com Port” (VCP)).
Feature #2: Protection Against Electrostatic Discharge (ESD)
If the operating environment is prone to voltage spikes and surges then a USB converter that protects against ESDs of up to 15 kV and against current surges of up to 600 W/ms is a wise investment. Make sure your USB to RS232 or USB to RS485 converter is designed for these tough conditions.
Feature #3: Supports A Range of Converter Product Offerings
It’s important that your supplier is able to understand the marketplace and provide various converter solutions to satisfy it. For example, some customers require only mini USB to RS232 or USB to RS422 converters, while others insist on multiport, industrial-grade converter hubs. A supplier that can support a range of USB converter products most likely is serious about delivering excellent products and customer service. While this may seem like a ‘soft’ feature, and more on the marketing side, it can be the decider if you have to choose from more than one supplier.
Feature #4: LED ‘Lights On’ Management
While this may not be necessary on the cheaper, single port converters, for multi-port USB to RS232 converter hubs, it’s a useful feature to have when first troubleshooting possible connectivity issues.
Feature #5: Compatible with USB 2.0 and compliant with USB 1.1
Most newer computers come with USB 2.0 ports but there are still those that have only the older USB 1.1 ports. Engineers showing up on-site with older notebook computers may appreciate this backward compatibility one day!
Taken together, when these five features are found in a USB to Serial converter product you can be confident that the device has been engineered to perform to a high standard.
