The Win7 laptop beside me has a back-panel COM1 port set to
9600,8,N,1.
Its Device Manager has an entry for "Ports (COM & LPT)."
Port Settings > Advanced accepts settings for COM1 to COM256. COM3 thru COM6 are "(in use)", the upper two for a USB cellular modem that appears as two virtual COM ports.
If you use an RS-232 to USB adapter, some don't use real RS-232 voltage lev els, like -3V to -15V for a logical true and +3V to +15V for a logical fals e, but use 0V for a true, and that doesn't work with some equipment. I'd e xpect adapters based on Cypress chips to be OK, but apparently the first ch oice is an FTDI brand chip, and they have driver software for every operati ng system. I think StarTech brand adapters are still good, but Cables Unli mited was also selling FTDI adapters that worked well.
The minimum is (for the DB-25 connectors) If it is a DE-9 connector instead -- on many newer computers) the pin numbers change, and I don't work with those much.
Data Ground from pin 7 to pin 7
Data leads: (assuming a crossover, with both ends the same time of RS232
2 - 3 3 - 2
If there is more needed (handshaking) add:
5 - 6 6 - 5
and maybe tie pin 20 on each end to one of the two before.
And to be sure to deal with voltage differences between the two chassis -- safety ground from pin 1 to pin 1.
No experience with Windows 7 -- sorry. (Nor with much of any other Windows, for that matter.) Way back when, I liked kermit for the transfers between unlike computers.
For unix machines, I would usually use tip or cu -- but those are unlikely to be found on a Windows box.
you will need a null modem cable and a232port on a computer. there are some usb to 232 adapters but not all will work properly because of voltage differences. I have a box of new null modem cables 15 ft if you need one. I ordered three cables and they sent me three bags of three. You will also set your baud rates to match as well as the other parameters, stop bits, data bits, parity and some other stuff so the two units can communicate.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.