USB to Serial


#1

i have gsm modem wavecom M1306B, because my computer havent serial port, i use Bafo BF810(USB To Serial Adapter). i have configure bits per second=8 115.200 bps, data bits=8,parity=none, flow control=hardware in Prolific USB to Serial Comm port(BF810 Driver). when i try to connect in hyper terminal, nothing character is displayed (i have configure the correct port, bits per second=8 115.200 bps, data bits=8,parity=none, flow control=hardware)in hyper terminal properties). in modem led on permanent.


#2

hello,
my answer is probably too late, but did you try setting flow control to none?
i download dwl files to modem with flow control set to none at 115200
hope you solved your problem


#3

For reference: Some usb-to-serial convertors do not use all RS232 pins. Choose one, which explicitly states that it is using all the pins, and provides a genunie replacement for a serial port. The ones not using all the pins do not work (I also have a laptop without serial port and working without problems)


#4

They can be made to work by adding an adaptor cable that “loops-back” CTS to RTS:

9-Way D-Type                  9-Way D-Type
         to Modem      Adaptor     from USB adaptor
(female contacts)       Cable      (male contacts)

TXD in  <-------(  3  =--------(   =----< TXD out
RXD out >-------(  2  =--------(   =----> RXD in

CTS out >-------(  8  =--+
                         |
RTS in  <-------(  7  =--+

GND ------------(  5  =--------(   =----- GND

You might also want to loop-back DTR to DSR:

DSR out >-------(  6  =--+
                         |
DTR in  <-------(  4  =--+

Of course, you no longer have any hardware flow control…!