RS232 Breakout Tester LED Monitor, DB9 Male to Female Breakout Module

This device works great for observing and debugging RS-232 stuff. Some folks complain about the test points not accepting dupont cables, they're sized for resistor leads, some breadboard cables (with round pins) and non-stacking arduino headers will also plug into them for use with dupont connector if needed (non stacking means the standard headers you'd find on arduino UNO, not the ones with long pins used on shields). They used the round socket strips because they had the same height as the dip switches. Photo shows RS-232 reconfigured with 10ohm resistors as an Agilent crossover cable, which solved the problem I got it to solve. The case was too bulky to plug directly into the back of my Agilent 34401A, so I used a stack of gender changers to get clearance.

Compact and easy to use. Seems like it’s good quality too!

This product worked well, reporting, in the form of red and green LEDs, the status of each line on a DB9 type serial port. The standard line assignments are indicated on the case, and a switch allows the lines to be individually opened or closed for testing. Jumper sockets are also available for electrical access to each line, and for other testing purposes. It does not require external power to run, and assumes standard line assignments and signal levels. It could be used for other DB-9 signal tracking keeping its original purpose in mind.The only addition I'd recommend would be a place on the tester body to store unneeded male-to-female retaining nuts. Some DB-9 installations have external retaining nuts, some have screw heads, and some have nothing. When there are external retaining nuts or screw heads, the retaining nuts on the tester must be removed to plug in the device. These are easily lost. A set of threaded holes on the body of the tester would provide temporary storage for the unneeded retaining nuts.

This breakout tester is absolutely essential for anyone working with serial communication on a regular basis.The problem with serial communication is that it either works or it doesn't, and there is very little, if any, sign of that's wrong, and there could be any number of things wrong.I cannot count how many times I've wired up a connection between two devices and had it not work. Did I use a null modem cable? Or is the device wired so I should be using a straight through cable? Is the device sending data? Maybe the baud rate is set wrong. Is the COM port I'm plugged into the right one? Or worse... what if two or more of those things are wrong?I guess I'll have to haul out other cables, a logic probe and a power source to run it, maybe a meter, and some little tiny wires to stick into those DB9 connectors to probe the pinout... Gimme an hour and maybe I'll have it working, you say to yourself....This one little simple gadget solves all of that. Do I need a null modem cable or a straight through, or is the cable really what I think it is? Flip two switches and place a couple jumpers to reverse the TX and RX lines, and find out, without hunting around for other cables or busting out a meter to figure out what kind of cable you have.Want to know if the host is sending data? Is the peripheral responding? Are the send and receive happening on the right lines? No problem, look at the LEDs on the front and I know, at a glance.If your communication is more complex and is using the other pins, there are LEDs to tell you those statuses too.Want to snoop the line? No problem, just grab an FTDI cable and some jumpers and you can spy on the communication using the jumper ports. Or, use a second one of these boxes and do the same.I cannot state enough how much time this saves and how useful it is. It's small enough to carry around in a toolbox, robust enough to get banged up a good bit over time, and requires no batteries or additional power sources, it's powered by the line itself.I only wish I had bought one of these years ago.

If you're trying to solder together an old RS232 cable and not sure your connections are right, this little pocket sized device will help you out. You can see most of the major signals such as TX, RX, CTS, RTS, DCD, DTR, etc. It's also possible to turn off the pin to pin connectivity and use jumper wires to re-route a connection to try and get your serial port working.The only downside is that no jumper wires are provided, but you can use some thin wire, paperclip or even bread bag ties to make the jump.Otherwise, handy little device to have on hand.

This thing is like the Swiss Army knife when you need to troubleshoot RS232 / serial communications. It can connect almost any possible combination of 25 or 9 pin cables, and can connect most signal to any other signal. The only thing I find kinda annoying is that all the connectors have standoffs, which doesn't work well when your existing cable already has standoffs! But not annoying enough to ding the usefulness of this thing.

It works very well. Use 22AWG solid wire. 24AWG works as well, but I find it a little sloppy. 22AWG fits perfectly and snug. Some people complain about the upside down DB9s - I say: “So what?”. It’s a great little tool. The photo shows a typical null modem configuration.

The rows of pin sockets on the front of the device are too small diameter to accept a standard component or jumper pin.