Finally got around to downloading and installing Test Controller. We know what took so long 
This is an impressive effort from HKJ 
After stumbling thru a few things we were able to get our DMM6500, DAQ6510 installed by LAN. Then our GPP-4323 and a pair of SPD3303X.
However we've tried the Hioki IM3536 and can't seem to connect, we know we have a good LAN connection as we can "see" the IM3536 with terminal connection from our Mac: "Connection to 192.168.001.119 port 3500 [tcp/rtmp-port] succeeded!".
Also tried with the TH2830 with a USB connection, also without success. We could "see" the USB connection with a terminal command ls /dev/tty.usbmodem* as "/dev/tty.usbmodem301" which was verified by plugging and unplugging the USB cable. Not sure how this should be entered into the serial address, so used com301 and get a "Dummy Device" response.
Anyone have any suggestions, we aren't up on this sort of stuff, and getting the IM3536 connected is more of a priority for starters.
Best
Did you edit the port number / verify that it matches on the IM3536 and in the device definition file? The default port number in the file is 03536.
For the ST2832, you need to make sure the port selected in the ST2832 says USBCDC, not USBTMC. I've not tried with a Mac, so I don't know what headaches might occur with that. TestController is not currently compatibly with USBTMC.
Even when correctly setup, I sometimes have to hit "Reconnect" a few times with the ST2832. The serial communication with it can be a little tricky. Adjusting buffer sizes sometimes helps with that sort of thing.
There are some notes to help with both devices in the definition files. For my ST2832, I had to remove the USBTMC driver before Windows would work with and install the correct USBCDC driver. I know you're on a Mac, so again I don't know what headaches it will throw.
On a Mac, try long-clicking to see if options popup.
There's a batch file to run debug mode in the TestController app folder. I dunno if that does anything on Mac, but it will show you the normal command / options.
Thanks,
Josh