APPA 106N RS232 Power

[imk]

Hello,
So after much research I think i have narrowed my MM search to the APPA 106N AKA RS Pro IDM 106N
Question is how is the RS232 PC interface powered, as i guess the optocoupler is to isolate the PC from the MM.
Hence there is no electrical connection from the MM to the PC's RS232 Rx data line and this to my mind would require a pullup.

I ask as if this is from RTS or DSR then what happens if you use a USB dongle, anyone tested it?

Many thanks imk