TRENDnet USB to Serial 9-Pin Converter Cable, TU-S9, USB to RS232 Serial Adapter, Supports Windows & Mac, 64cm (25 in.) Cable Length, NDAA Compliant, Plug & Play, White

I'm trying to get a 20 year old microcomputer back up again. It requires a serial terminal interface which I no longer have (because I stupidly gave away the VT100 type terminal I used to communicate with it). Rather than buy one that would be expensive and of little future use, I started looking for a more modern solution. Having been working in electronics for many years, I have learned that one can get lucky and everything works okay the first time. Failing that, troubleshooting digital hardware can be difficult and time consuming. As a learning experience with new hardware and to simplify getting the basic RS-232 communication link back up, I purchased an Arduino processor board and an RS-232 "shield" to go with it. The shield simply converts the digital levels from the Arduino to RS-232 levels. These Arduino products are great, very flexible, and relatively cheap. Programming software is free and the language used is more or less "C". Plenty of programming examples are in existence. So, I was able to get the Arduino's RS-232 output going (looping output data) which I first looked at with a scope. Next, I brought up an old tower PC running XP. I started using this computer because it had a DB-9 RS-232 port and a terminal program known as "Hyperterminal". After XP, Hyperterminal has to be purchased separately. Hooking up to the PC and Hyperterminal worked just fine. Next, I wanted to get rid of the tower PC and run things from a small ACER netbook portable. This is where the Trendnet product comes in since the ACER doesn't have a DB-9 port. I was hoping the driver for this device would install automatically but it didn't so I had to use the supplied CD. Since the ACER didn't have an internal CD drive, I hooked up and external one through a USB port and loaded the driver without incident. If you don't have an external drive, I imagine you could use another computer to load and then send the file over your LAN. The next stumbling block was that Hyperterminal was NOT installed on my ACER. Rather than try to figure out why, I looked on line and found another (free) terminal program called RealTerm. Hooking the Trendnet to the Arduino DB-9 and an ACER USB port worked fine. The only thing I noticed, which could be a problem for some, was that no "thumbscrews" were provided on the Trendnet DB-9 end. This end stays mated okay with the DB-9 end on the Arduino, but I don't particularly like to leave DB connectors unsecurred to each other. One could use a short jumper cable, but who needs extra work and cost. Over the years, I have purchased several other Trendnet products and found that they generally did what was advertised and were of good quality for the price.

These are great. Unlike a lot of the cheap ones, these provide actual EIA-232 (RS-232) bipolar voltage levels. Many/most of the cheap ones don't, they only provide positive voltage signals. For many devices, that doesn't matter, but for some it does and this one will work when others don't. So, this is the one to get if you just want it to work with _anything_ using EIA-232.USB VID/PID shows it uses a Prolific PL2303GT USB/serial bridge chip. High quality, highly recommended.

Excellent

Before you buy, BE AWARE that this adapter has two female nuts next to the plug for securing the serial port to the adapter. I was connecting this to a Bosch CDR tool which has a serial interface. This tool also has two female nuts next to the serial plug. Since neither one is male, they could not connect. The nuts would not even let the adapter plug touch the serial port on my device. I thought I could simply unscrew the nuts on the adapter but they are permanently attached. In order to remove the adapter nuts I had to pry open the plastic casing around the serial end and use a Dremmel tool to cut away the backing of the female nuts on the other side of the mounting plate. This is a delicate process and it would be easy to break the soldered connections by the strain relief if you are not careful.Once these were removed, I installed the windows seven drivers from the CD and the adapter worked perfectly. The CDR Tool immediately recognized the adapter as COM3.If the device you are connecting to has male threaded screws for securing it to a serial cable, this device will work perfectly out-of-the-box. if your device has female nuts intended to be connected to mail threads, prepare to do a little extra work before you can use it.

This is the fifth cable now and voila, it works with my diagnostic kit-MSV-2. Before trying the trendnet, it was disappointment after another not to mention the waste of money with useless serial cables I cant return from here Kenya. Thanks trendnet I had almost given up

One of my few 5 star reviews, but definitely worth it. I needed to connect a VERY old Windows XP laptop to a piece of audio gear that seemed to be failing, and the only access was via an old DB9 com port using the vendor's no-longer-supported software. This cable comes with a driver CD and a simple set of instructions: 1) insert the CD, 2) click on "Install Driver", and 3) plug in the cable. The driver installation was very fast and completed without any problems. The old (and slow) Windows XP laptop immediately recognized the device and loaded the drivers when I plugged in the cable, giving me the "hardware ready to use" message in about a minute. It installed the connection as COM6, so I just needed to swap that with COM1 (which the audio-gear software needed to see) and the software connected with the device and I was able to restore operations. The DB9 end is male, so if you need something longer than 2 ft, a standard DB9 male to female cable connects securely, since this cable has the connection nuts on the DB9 connector which the standard cable can screw into to hold them together. For less than $10 US, this was a bargain and helped me save a church several thousand dollars since they didn't have to replace the hardware. The worst thing about the product was the molded plastic packaging that you have to cut to get to the product.