serial ports

[jeffx]

Yes, I do hava several multimeters.

 

[BraveSirRobbin]

Yes, I do hava several multimeters.

OK, put one of the multimeters on "OHMS" selection (symbol shaped like a horseshoe). If you have a manual scale type place it on the smallest scale (i.e. vs an autoscale meter which only would have the OHMS selection).

You should see a ONE or "OL" or some indication of "infinite" resistance. Touch the meter leads together and you should see something like 0.1 ohms on the meter.

Now place one of the meter tips on the end of one of the pins on the DB-25 connector. Place the other on its corresponding pin on the DB-9 connector. You should see 0.1 ohms. If you see the "infinite" resistance, you do not have "continuity" (the pins are not on the same wire).

Another quick check, especially if you are doing any soldering, is to check for "leakage" between the pins. This really isn't a problem in your case as it would be pretty hard to do with those adapters. But, for those of you playing along at home, here is how you do it.

Place the meter in it's largest OHMS scale (or just OHMS for a multiscale type meter). Touch the meter leads together and you will see similar results as above. Separate the leads and you should see infinite resistance.

Now place on meter tip on a pin. Then, touch the other tip on all of the pins and the outer ground shield (if applicable). You should see the same infinite reading for each pin touched by the second lead (except for the pin that it is actually connected to of course ). If you see any reading, you have leakage between the pins. As I stated before this could be due to someone "stapling" a wire down on a stud, oversoldering pins, etc... This step is important to do if you are installing say, a security system so you know all of the wiring is not damaged. All of these steps (ringing out cabling) is explained in more detail in my Installing a Home Security System How-To.

Again, this does not need to be done in this case.

 

[BraveSirRobbin]

jeff;

How are you making out on this? Did you try reversing pins 2&3 on the DB-9 connector?

 

[jeffx]

BSR, had to take a day or 2 off from working on this to spackle and prep the walls of the baby's room for painting and to run another intercom station. How would you recommend testing the continuity of the connections when the my alarm panel (serial device) and PC are on different sides of the house (did I miss that part in your instructions)?

 

[jeffx]

Tonight I'm also going to try installing HAL2000 on my laptop and connect directly to my panel with a Belkin DB9 to DB25 cable.

 

[jeffx]

OK, after fixing a minor plumbing emergency yesterday I finally got scientific about this problem.

First, I disconnected the Alarm Panel Serial device I was using and bought the "officially supported" device with all the cables from an authorized dealer that can provide me technical support if needed.

Then I connected my laptop directly to the alarm panel, using the cable provided with the serial device.

IT WORKED! :unsure: :lol:

I was able to arm, disarm and observe zone status from HAL2000!

Next, still at the panel, I connected my laptop to the panel using the DB-9 to RJ-45 and RJ-45 to DB-25 connectors, with a 6 foot patch cable in between. Everything still worked!

Next, I tested my twisted pair connection (from panel to smart closet) by connecting my laptop ethernet on one end and to my broadband router on the other end. Viola! Internet worked perfectlly.

Now for the bad news. When I made the serial connection from laptop--DB9/RJ45--PatchCable--CAT5e--RJ45/DB25--AlarmPanel: no communication.

:lol:

I am going to re-do the pins on my DB/RJ45 adapters so that they run through the recommended twisted pair combinations (from BSR's link). I can't think of any other reason it's not working. For whatever reason, the signals aren't making it accross the 25 feet of twisted pair (CAT 5e).

I am optimistic, though, as now it is down to a serial cabling issue from Panel to closet as I have verified everything else.

 

[jeffx]

Just found out you can't re-pin the RJ45/DB adapters :unsure: Enough is enough so I just ordered a 25 ft serial cable and I'll run that from Panel to Smart Closet. Now, on to Powerhome and linking my Insteon devices

 

[BraveSirRobbin]

Just found out you can't re-pin the RJ45/DB adapters :unsure: Enough is enough so I just ordered a 25 ft serial cable and I'll run that from Panel to Smart Closet. Now, on to Powerhome and linking my Insteon devices

You need the right pin extraction/insertion tool to take those pins out (Rat Shack part number 276-1426).

Also, you could just do a pin to pin check on pins 2, 3, and 5 and compare your cable that works with the one you made and see if any differences exist (ringing out your cables with a multimeter as described above). This would tell you why it wouldn't work.

 

[jeffx]

Found a few toss-away 30 foot serial cables at work. I'm going to give those a try tonight. That will save me a few bucks from having to buy one now. If I need to run any additional serial connections in the future, I'll try the rest of your suggestions. Thanks again.

 

[jeffx]

My 30 foot serial cable run from my panel to closet worked perfectly with my alarm system and HAL2000 running on my laptop. When I switched the cable over to my desktop with HAL2000, it still didn't work!

Could there be some incompatibility with the serial ports on my desktop (AMD Athlon XP with NVIDIA mother board) and my alarm system? I checked all settings and advanced settings and they were identical on both laptop and desktop (default settings). Any known issues with the serial ports on NVIDIA motherboards? I've tried both serial ports both with and without a NUL modem.

I'm going to install HAL2000 on the PC that runs my DVR software to see if that works (Intel Pentium IV). It may have been that all my previous serial connections WERE GOOD, but that the configuration or the serial ports on my HA PC have issues. Live and learn...

 

[BraveSirRobbin]

My 30 foot serial cable run from my panel to closet worked perfectly with my alarm system and HAL2000 running on my laptop. When I switched the cable over to my desktop with HAL2000, it still didn't work!

Could there be some incompatibility with the serial ports on my desktop (AMD Athlon XP with NVIDIA mother board) and my alarm system? I checked all settings and advanced settings and they were identical on both laptop and desktop (default settings). Any known issues with the serial ports on NVIDIA motherboards? I've tried both serial ports both with and without a NUL modem.

I'm going to install HAL2000 on the PC that runs my DVR software to see if that works (Intel Pentium IV). It may have been that all my previous serial connections WERE GOOD, but that the configuration or the serial ports on my HA PC have issues. Live and learn...

Do the serial ports show up as working OK in device manager?

 

[jeffx]

Yes, the serial ports do show as OK in device manager.

 

[electron]

Can you define 'it didn't work'? Can you connect with Hyper Terminal? Do you get any error messages? Do you use any USB->Serial adapters or Serial port hubs?