Not sure if anybody is still using these things but I had the opportunity to repair one after it was damaged in a Florida storm (see? I keep saying all the stuff blows up in Florida and Texas). Figured I'd do a quick write-up in case anybody else needs to fix one. The iLink units connect to the comm port on the intellitouch via rs485, and then to a pc (or some other automation system) via rs232, or a regular old serial port.
This particular unit was mounted indoors and hard-wired to the outdoor panel's comm port... there was a lightning strike which took out both the rs485 comm chip AND the rs232 serial chip, but miraculously everything else ended up being just fine.
I got the unit and plugged it into my lab supply so I could see how many mA it was drawing... I saw 43mA which seemed close enough to the other one I had (38mA). I connected it to the comm port on a test intellitouch board and it hit the 150mA current limit, which told me for sure that the rs485 chip was fried. I pulled and replaced the rs485 chip:
After that I tried to connect to it with a terminal emulator (I use Putty) and while I saw the rs485 LED flashing, I couldn't get anything in the terminal. Did a quick check of the rx/tx lines on the rs232 chip and they should have both been 5v, but one was only 0.6... so the rs232 chip was bad (it's a max232e). As a quick test, I pulled leg for the bad line, connected an external serial board and was able to talk to the board using Putty. Pulled the max232 chip and replaced it...
After replacing that chip (and repairing a pcb trace that pulled up), the board was fixed.
This particular unit was mounted indoors and hard-wired to the outdoor panel's comm port... there was a lightning strike which took out both the rs485 comm chip AND the rs232 serial chip, but miraculously everything else ended up being just fine.
I got the unit and plugged it into my lab supply so I could see how many mA it was drawing... I saw 43mA which seemed close enough to the other one I had (38mA). I connected it to the comm port on a test intellitouch board and it hit the 150mA current limit, which told me for sure that the rs485 chip was fried. I pulled and replaced the rs485 chip:
After that I tried to connect to it with a terminal emulator (I use Putty) and while I saw the rs485 LED flashing, I couldn't get anything in the terminal. Did a quick check of the rx/tx lines on the rs232 chip and they should have both been 5v, but one was only 0.6... so the rs232 chip was bad (it's a max232e). As a quick test, I pulled leg for the bad line, connected an external serial board and was able to talk to the board using Putty. Pulled the max232 chip and replaced it...
After replacing that chip (and repairing a pcb trace that pulled up), the board was fixed.
