Configure IR port for one-way serial

javedwahid

I'm trying to use an IR port as one-way serial, but it doesn't seem to be working. Is there anything special/different that needs to be done to use an IR port for one-way serial?

Thanks,

Javed

[Deleted User]

You will need SET MODE and SET BAUD for your communications.

Check out PDF page 100 for options to the port:
http://www.amx.com//assets/manuals/NetLinxControllers.WebConsole-ProgrammingGuide.FMv4.pdf

Hedberg

Also note that the + connection on the IR port is transmit and the - terminal is ground. I don't know why, but the guys with screwdrivers and soldering irons seem to have an uncontrollable urge to connect the - connection on the IR as if it were receive instead of ground.

javedwahid

Chris, thanks for the post. I set the mode to "SERIAL"

Hedberg, I double checked that and it's connected right.

Problem not is that it still doesn't seem to be working. I know my commands are good, because I tested them over a true serial connection and it works. Is there anything else that I'm missing / can check?

Thanks,

jdonachiue@shaw.ca

Check the Device Baud Rate...

Just a thought as I have had Monitors that have a "DEFAULT" Baud Rate,
but when I get to them the Rate is not set @ the Default...

Hedberg

javedwahid wrote: »

Chris, thanks for the post. I set the mode to "SERIAL"

Thanks,

Try "set mode data"

edit:

Ok, I don't know why this is the way it is or why it is so poorly documented, but when you want to use an IR port for serial communication, you set the mode to "data" and not to "serial". BTSOOM

Hedberg

Some more thoughts on this.

If you take a voltmeter and measure the idle voltage on a normal AMX RS232 port you will find it to be about -9v to -12vdc. I just measured it on an NI700 and it's about -9 to -9.5vdc. That is within the RS232 standard. If you set your IR port to "data" and try to measure the idle voltage, I don't believe you get a value -- maybe it's close to 0vdc. That is not within the RS232 standard. Apparently, the RS232 function of the IR port does not maintain the proper idle voltage. I don't know how to measure the modulated negative voltage when the IR port transmits without a scope (which I don't have), but I'm told that it is less (i.e. not as negative) than the RS232 standard calls for. But, it's clear that the IR port in data mode will work as a one-way RS232 port because we do this sort of thing all the time.

I think that what all this means as that it will work with a lot of equipment and works best at short distances and low baud rates. When we use it, it's almost always with Extron switchers which work at 9600 baud and almost always function flawlessly so that not having the feedback from the device is easy to work around.

For testing purposes, you can hook it up to your laptops RS232 port, or your USB adapter. In my experience, if configured correctly, it will work either way for testing. If you need a decent RS232 terminal program, try out Indigo -- it just works.

javedwahid

Changed the baud rate to 19200 and updated the DMP to use this baud rate, but no success there

also tried using SET MODE DATA, but that didn't work either.

Any other ideas on what it could be?

Thanks,

javedwahid

Tried setting mode to DATA and using low baud rate: 9600. but no luck

do I need to modify the command in any way since it's going out the IR port or do I just send it the same way I would through the RS232 port?

Thanks,

ericmedley

javedwahid wrote: »

Tried setting mode to DATA and using low baud rate: 9600. but no luck

do I need to modify the command in any way since it's going out the IR port or do I just send it the same way I would through the RS232 port?

Thanks,

Post the code. Perhaps we can help.

javedwahid

Got it to work, Ended up using baud rate or 9600 and SEt MODE DATA. Not sure if anything else changed but it finally works, so thanks to everyone for their input.