Weird issue with Digi One IAP & Dyadic servo amplifier

We've been using a Digi One IAP as a Realport device (Serail to Ethernet) to allow a device (Dyadic actuator & amplifier - http://www.miraiintertech.com/home/scn6.php) but it has been flaky, to say the least. Sometimes, the software could connect immediately, but sometimes it would take 20 or more tries. Sometimes, the IAP had to be rebooted several times.

Yesterday, on a whim, I tried usin an Automation Direct FA-ISOCON to convert the RS-485 signal from the amplifier to RS-232. Using an Automation Direct D2-DSCBL programming cable, I connected the FA-ISOCON to Port 2 of the IAP and, suddenly, it's working perfectly.

It's really strange. The IAP should be able to accept RS-485, RS-422 or RS-232 on Port 1 without issue (assuming DIP switches are set properly).

Has anyone encountered a similar issue? I've used a lot of IAPs and Realport devices for similar applications and they've performed very well.

i found that when the digi one IAP couldn't connect to one of the slaves it would reboot itself rather frequently. If the serial connection to the digi one IAP didn't work but through an isolator it did I would suspect it is a serial issue such as not having a common ground or as you say DIP switches for baud etc.