Hello everybody,
have you anyone used DB9-USB-D3-F - FTDI - MODULE, USB TO UART, 1 CH, FT232R | Farnell ? I need them as USB/RS232 converters.. I have bought two modules, but I cant send any data into PC from any of them. If I connect logic analyzer to TXD pin, so I can send data from PC terminal to "logic analyzer" (so FTDI driver should be OK). But when I connect RX to TX (to make a loop), so transmitted data never come back to terminal. I have WIN7.
Thanks for any idea..
Uf, it already works 
There are two possibilities: 1) I am stupid 2) Datasheet is "little" bit confusing. Please tell me, what is correct..
1) I have FEMALE USB bridge
2) If I connected logic analyzer to pin 3 (red circled), so I could "see" sent data from terminal.
3) I have connected red circled pins together to make a loop. If the green rectangle stands for PCB, so it seems logically to me, that FTDI bridge must be under the PCB with pins upwards on the picture. I admit, that I have not read the text under the picture. I have expected, that "UART Transceiver" is a part of MCU..
3) If I connected red circled pin together to make a loop, so nothing came back to terminal => That was my problem.. Till now..
4) I have connected green circled pins together and every sent data from terminal immediately came back..Loop works !!!
Datasheet can be found here: http://www.farnell.com/datasheets/1812681.pdf 
vivi wrote:
Uf, it already works There are two possibilities: 1) I am stupid 2) Datasheet is "little" bit confusing. Please tell me, what is correct..
The male version is designed to replace the 9-pin male DB9 connector on a PC. In every PC I've seen, the serial connector is male DTE (Data Terminal Equipment) so that the PC acts like a terminal. The female version is designed to replace a female DB9 connector on a modem, also known as DCE (Data Communications Equipment). With these connectors, you can connect a terminal (or PC) to a modem with a straight-through cable with a male connector at one end and a female connector at the other.
The DB9 pins are mirror-imaged compared to each other. If you look at a male DB9, pins 1 and 6 are on the left. If you look at a female DB9, holes 1 and 6 are on the right. That way when you rotate one of the connectors to link them together, pin 1 will enter hole 1, etc.
I think your error is that the figures at the top show the pinout looking through the module with X-ray vision. That's why the red-circled pins in the diagram match the green-circled pins in the photo. They probably drew it this way so it matches the top side of the PC board.
Yep, it's really, really confusing. The best way to deal with RS-232 is to get an "LED line monitor", preferably as part of a "break-out box". That way you can plug a cable between the RS-232 port and the LED monitor and see which lines are active instantly.
vivi wrote:
Uf, it already works There are two possibilities: 1) I am stupid 2) Datasheet is "little" bit confusing. Please tell me, what is correct..
The male version is designed to replace the 9-pin male DB9 connector on a PC. In every PC I've seen, the serial connector is male DTE (Data Terminal Equipment) so that the PC acts like a terminal. The female version is designed to replace a female DB9 connector on a modem, also known as DCE (Data Communications Equipment). With these connectors, you can connect a terminal (or PC) to a modem with a straight-through cable with a male connector at one end and a female connector at the other.
The DB9 pins are mirror-imaged compared to each other. If you look at a male DB9, pins 1 and 6 are on the left. If you look at a female DB9, holes 1 and 6 are on the right. That way when you rotate one of the connectors to link them together, pin 1 will enter hole 1, etc.
I think your error is that the figures at the top show the pinout looking through the module with X-ray vision. That's why the red-circled pins in the diagram match the green-circled pins in the photo. They probably drew it this way so it matches the top side of the PC board.
Yep, it's really, really confusing. The best way to deal with RS-232 is to get an "LED line monitor", preferably as part of a "break-out box". That way you can plug a cable between the RS-232 port and the LED monitor and see which lines are active instantly.
