Re: RS232-to-USB adapter with dial-up modem

[S D <sundimi@yahoo.com>]

> From: Phil Requirements <simultaneous@comcast.net>
> 
> What are you using to try to dial out?

I'm using pppd and the respective pon/poff scripts and configuration files. This configuration works fine with the modem when the modem is connected via a RS-232 port. When the modem is connected via a USB port it doesn't. The only change in the configuration appears to be the device (/dev/ttyS0
vs /dev/ttyUSB0) to which the modem is attached to.


> Perhaps a silly question, but does the adapter require that you install a driver?

There's a CD that came with the cable but it only contains stuff for Windows. The vendor did not explicitly claim it'll work with GNU/Linux. Linux does seem to recognize the modem, in the log it says "usb 1-9: ch341-uart converter now attached to ttyUSB0", so it looks like the problem isn't with the missing driver(s).

I'm beginning to think John Hasler was right when he said that "they've failed to implement enough of the modem control lines and/or gotten the voltages wrong" and suggested to throw the cable away and buy a new one. That would be a pity though.