Help: USB to RS232 - How to test?

[louarnold]

How do I determine if the USB port is actually getting data to/from the system's COM port?

Some info:
- I purchased a Generic USB to RS232 adapter based on a PL2303 chip.
- I have installed drivers on both Vista Home Premium and Windows XP SP3 machines.
- The driver that came with the adapter seems to have installed properly.
- I have RealTerm installed.
- I jumpered Tx to Rx plus other pins on the male DB9 connector.
- I sought help from Prolific (re PL2303), but found nothing helpful there.
- It is the USB port that adapter is plugged into. The RS232 DB9 will go to serial device once its tested.

But I don't know how to look for data passing through the adapter. What I type on the keyboard does not show up on the RealTerm screen.
I am stumped, and about to cut the vinyl covers of the adapter to see if I can find the problem that way.

 

[srizbf]

please check what 'COM' port number your usb2rs232 adapter is mapped into.


then use the same COMx in your 'realterm'.

post your test result.

srizbf
2ndjune2010

 

[louarnold]

please check what 'COM' port number your usb2rs232 adapter is mapped into.


then use the same COMx in your 'realterm'.

post your test result.

srizbf
2ndjune2010

The port was COM4. I tried RealTerm, but there was absolutely no data shown. No data that I typed came back. Not when I jumpered TX to Rx alone, nor when I added jumpers for RTS->CTS, DTR->DSR->DCD. This is also true on XP.
I'm not sure what you expected me to post.

 

[srizbf]

i too have experienced problem with similar adapter.

after getting one more it was working.
(not tested with realterm)

i am not sure why some are working some are not working.

may be the adaptermakers(mostly chinese) may know.

srizbf
2ndjune2010

 

[louarnold]

i too have experienced problem with similar adapter.

after getting one more it was working.
(not tested with realterm)

i am not sure why some are working some are not working.

may be the adaptermakers(mostly chinese) may know.

srizbf
2ndjune2010

What terminal software did you use to test yours?
Using RealTerm, I can see the Tx data indicator flash when I type or use the "Send" tab. But sometimes that indicator stays on until I restart RelaTerm.