The Truth About USB to Serial RS232/RS485 Adapters
Most newer electronic devices can be connected and communicate with a computer by a USB cable, however many devices are still using the older type of communication protocol called serial RS232 or RS485. To connect devices with a Serial RS232/RS485 port you need an adapter cable called a USB to RS232 adapter or USB to RS485 adapter, depending on if your device is using the RS232 protocol or the RS485 protocol.
USB to RS232 or RS485 adapters are often used for connecting devices such as GPS navigation units, sensors, meters, loggers, cameras, printers and other standard and special devices to a personal computer.
Most people assume that these adapters are compatible with ALL operating systems and ALL devices, however this is far from the truth.
When you invest in a USB to Serial adapter you usually pay for what you get. Many websites are selling low-cost USB to Serial RS232 adapters for $9.95. This sounds like a great deal, however when you receive the adapter and connect your device to your computer you will most likely get disappointed, because in most cases the adapter will not work properly with either your computer or your device. The major reason for this is that the low-cost adapter is made with a low-cost processor chip. These low-cost processor chips have limited compatibility with the majority of devices and the Microsoft Windows operating system.
Limited compatibility means that the adapter/drivers might or might not work with your Vista/7 computer, it all depends on your computer's particular hardware, installed Windows components and service packs, conflicting drivers or other peripheral devices, and even your processors bios version.
Usually the drivers work fine with Windows 98, 2000 and XP, however when it comes to Windows Vista and Windows 7 the problems starts showing.
The drivers for a low-cost USB to Serial the processor chip are very often poorly written programs which makes the adapter unstable and unreliable and not fully compatible with Windows 7 and other current operating systems. Because of this you will in many cases be unable to make a low-cost adapter work with Windows 7 and Vista and you can expect some of the following typical errors:
- Computer freeze
- Invalid debug DLL
- Computer crashing
- Driver problems
- Unable to connect to your device
- Unable to establish a COM port
So what do you need to look for to find a good quality USB to RS232 adapter?
First of all you need to determine which operating system you will be using the adapter with. Windows 98, 2000, XP, Vista, 7, or maybe Mac or Linux. If you are using Windows 98, 2000, XP or Linux you might be lucky to find a low-cost adapter which will work for you, however if you are using Windows Vista, 7 or Mac you need to be willing to spend between $20 - $30 for a good quality adapter which will work with your device and Windows Vista/7. Try and find out what processor chip is inside the adapter, good processor chips are FTDI, Silicon Labs, MosChip or Oxford Semiconductors. If you find a USB to Serial RS232 adapter with any one of these processor chips it will most likely be compatible with your device and any version of Windows, Linux and Mac, and you will be able to easily install the drivers and communicate with your device.
To learn more about serial communication, products and support please go to www.USconverters.com
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