We are converting a supermarket from Com-Trol 4000 controllers to one Danfoss Ak255. I'm having trouble backing up the software with an RS232-to-RS485 converter. It sees the controls individually when I hook them up, but doesn't see anything when I hook up to the group bus and scan. Every unit I tried timed out at about 37% or 5 sectors, which the tech is telling me means it probably isn't getting anything. I see the red LED on the CPU board flashing sometimes during the download attempt. Tried swapping the comm chips between the group and local busses, no difference. I have an RS484-to-USB adapter on order. Hopefully that will do it. Otherwise I'll be going off 10 year old backups I found on a floppy.
Any other suggestions besides the USB adapter?
I also have to get communications going to some Trane units with CIB (computer interface boards) in them. Most likely will be replacing them with CTI boards and using contact closures, since there's a stack of old CIB boards sitting in the HVAC control panel.