RS-232 LED Link Signal Tester - DB-9 Male to DB-9 Female Connections for Serial Communication Monitoring

Works perfect.

We were troubleshooting some 232 devices and codes, werent sure if everything was correct (some existing wiring and equipment). Put one of these in line and instantly know weather the wiring is correct or not! Saved lots of time and worked like a champ. You can also see little blinks when data is sent, it is kind of Suttle but there.

I like some other reviewers know for a fact that serial connectivity is not dead, finding a tester for DB-9 is not off-the shelf available for sure and finding this on Amazon was a blessing. I was in need of a test unit that was inline and simple to use and understand for checking signals from a control panel to an RS-232 external control port to mounted video projectors. I have to ascertain when a projector does not turn on or off from the wall controller if it is the wall controller / wiring, or the projector - if I call the wrong vendor responsible for warranty / repair I have to eat the service call cost. Having a small test unit with a visual indicator makes the diagnosis very simple. I did not find the LED indictors "dim" as some others have mentioned, mine were nice and bright, and exhibited no "bleed over" to the LED next to it. This unit is rugged and does what it says it will do, I did find like some other reviewers that the nuts next to one side of the connector get in the way when not mating to a cable but directly a device, simple to remove however and not a problem at all. I would recommend this to others.

It does what it says it does and does it well. The LEDs give you a very clear indication of what's going on inside your serial cable.Only caveat is that this is designed to be a pass-through device (one side is male, one female) but both sides have the "female" retention screw holes. This means you can't plug it directly into pretty much anything, because pretty much all computer and even device serial ports also have the female screw holes. If you take the screw holes off with a hex driver, the metal shielding comes with them, so you end up with an unshielded connection. Your choice is either deal with that or get two M->F cables where both ends have the screw threads and put this in the middle. I ended up using a little Krazy Glue to glue the metal shield to the plastic casing, but without the screw holes it's probably not even doing anything anyway. Just a heads up - you may have to do a little hacking, or get extra cables with the correct ends, to get this to attach to anything.

The led tester work great for computer or circuit bored testing to see if you are getting a signal of of a circuit board. It's pretty easy to use if the light lights are flashing it means it's transmitting data. Over all I thought it was a well made tool and I use it for uno projects and visual basic programing with the RS-232 port.

This can be used as a pass through device. We were using it to test an output stream going into a network adapter that does not have an activity light. It worked great! I will probably order a few more for our tool kits in the near future.

Though devices using serial connectivity are becoming a thing of the past, there are still a good number of devices that are not available with native USB connectivity and require serial port connectivity. Unfortunately, serial devices are not as plug-and-play as USB devices and thus often require some level of troubleshooting to get them up and working. This handy little link tester can be invaluable in determining if the serial connection is mated properly and if communications is occurring. I have used a number of these types of devices over the years and this particular 9-pin device is very convenient. The only drawback is the LEDs are not as bright as I would like to see. If you are in a brightly lit room or out of doors, it may be difficult to see the indication. Overall, I give this tester a thumbs-up.

This device is perfect. The LEDs are TWO COLOR LEDs, which are lit green for high voltage (not-asserted) and red for low voltage (asserted), so you can tell TX from RX without having to transmit data -- very easy to tell the most common issue which is whether it's a DTE o DCE (and whether you need a null modem or not.) You can immediately see whether modem controls are active, even if they're not being asserted.The only thing that would make this better would be jumper holes and jumper wires, to make a quick fix for two connectors that don't match. But that would make it a breakout box, not just a tester.