Well, I see 220 people were attracted to view my post from the description but there were zero answers so I'm assuming others may be interested in my findings. The guys who already figured this out will find this very basic but for us newbies who don't know up from down, I hope this helps get you over a hurdle so you can use COM1 for "transparent" (my definition - standard RS-232 communication that you normally take for granted when you plug a cable from your computer to an RS-232 device).
In my case, I need to have a transparent RS-232 link to my remote SO2R station which will handle my PLC based control system (128 I/O for antenna switching, rotation and misc. items). I could not find a simple and direct set of instructions to make this work but here is a check list to do this one job now that I've stumbled on it.
1) Use a null modem cable on the RADIO end between the RRC and the RS-232 device. (I just used a standard off-the-shelf NULL modem cable but you could make one that just uses 3 pins RX,TX,GND).
2) Under the SERIAL settings of each RRC, use the MODE 3, char timeout setting. MODE 1 was recommended but it was VERY slow and I found MODE 3 to be great and very fast.
3) Make sure the baud rates match your RS-232 device;i.e. if your device runs at 38,400 8N1, make sure each RRC is set the same way.
4) On the CONTROL RRC, make sure you don't accidentally leave the "Use USB COM Port as 1" turned ON. It has to be OFF if you want to use the DB9 COM1 port on the CONTROL RRC.
5) Make sure you click the CONNECT button on the status page of the CONTROL RRC before you try to see if serial data is flowing. The yellow LED on each RRC will light when a solid connection is establish.
All the other setting are fairly unimportant if you ONLY want COM1 communication but this will help you isolate any issues when you test on your home LAN like I'm doing. I'm open for any questions but remember, I'm a newbie and use the hit or miss technique to figure things out so don't think you will be getting an answer like a PHD in EE would give. ;-) My direct email, if needed, is K5WA at arrl dot net.
Good luck!
Bob K5WA
