just a few questions on rs232

[ghostman11]

thanks fot all the info guy's. the main project isnt actualy mine, my bit was simply a fan controller for a single fan. the idea is/was to be able to add in upto 250 fans, the clever bit is all done with the software on the pc side. my part is done so i can get back to my own projects! one thing i would like to be able to do is read the serial port on the pc. if anyone knows any good tutorials for visual c# can you point me to a good link.


cheers jason

 

[blueroomelectronics]

You could try multi drop RS232, a MAX3180 is an elegant solution for a single input RS232 receiver. You're likely going to have problems with more than a few units over a few meters.

250 taps will require some special buffering even for RS485.

Better yet get an RS232 to 485 or 422 converter and go with that. (RS485/422 uses differential signaling)

 

[ghostman11]

You could try multi drop RS232, a MAX3180 is an elegant solution for a single input RS232 receiver. You're likely going to have problems with more than a few units over a few meters.

250 taps will require some special buffering even for RS485.

Better yet get an RS232 to 485 or 422 converter and go with that. (RS485/422 uses differential signaling)

i think in future if i came up against something similar i would probaly look at CAN, the fans and controller are very close to the pc. it was a project being done at the uni, so i ended up getting involved, i didnt want to spend much time on it as personaly i think the whole thing will be binned in favour of something better.
although i no longer farm once i have moved to the new house i will build a couple of incubators and have a few birds around, i also hope to get back into fish breeding as i have three lakes at the new place and would be great to have the time again to keep a large freshwater aquarium, so i have plenty of scope for projects to keep me busy! i had a look at the max3180 i can see why you like it! it's something i might try on my next personal project. for now i am trying to learn to write a app on the pc to talk to a pic so i can control a pic via pc and log data etc, it's a bit of a learning curve but c# seems a realy nice language although a bit BIG!! i can do alot of the simple stuff with it but haveing trouble adding netbar gauges and getting them to respond! i cant seem to find decent idiot proof docs for it lol i only have the eval DotNetBar but i will probally buy it once i figure out how to use it