USB-CIF31 is a true USB to RS232 interface converter

the driver simulate the computer's USB interface to the traditional RS232 serial port (commonly known as the COM port), which can be used on a variety of programming software, communications software, monitoring software and other applications. The working power of the cable from the USB port, no external power supply needed. The light-emitting diodes on the converter box indicates power status and data transceiver state.

The RS232 port of USB-CIF31 is standard DTE interface (DB9M pin holder, the same as the computer's RS232 serial port), the signal arranged as the following table:
Pin No.
Signal names
Explain
1
DCD
Carrier signal
2
RXD
Receive data
3
TXD
Send data
4
DTR
Data Terminal Ready
5
GND
Signal ground
6
DSR
MODEM ready
7
RTS
Request to Send
8
CTS
Clear to Send
9
RI
Ringing signal

USB-CIF31 simulats RS232 serial port perfectly, and can even perform hardware I/O operations directly,for programmer just like working on physical RS232 port. USB-CIF31 support the vast majority of PLC programming cable, this is essentially different from similar products commercially available.
Features

Support Windows 7/2000/Windows XP (WinNT4/95/98/Me/DOS NOT SUPPORTED).
Power LED indicator.
Obtain power directly from the USB, no external power is required
DTE RS232 port, DB9M pin
Reliable performance & reasonable price