usb to serial port convertor

[sekhon]

Good morning sir

                           Thanks for helping me . Now i start working on usb to serial convertor . Installation has been done . Now new problem is coming before me i.e related to loopback test . Comport which is already present on pc give positive test when loopback test is performed. But usb to serial convertor don't do so actually i think problem get arised due to serial port because when i short 2 and 3 they don't get short but 3 and 4 get short and produce beep sound on multimeter (connectivity)....so, i want to know that my estimation regarding cable is right or not and please tell me what i do next to solve this problem. Thanks 

[Dennis_Knutson]

I have no idea what you mean by "when i short 2 and 3 they don't get short but 3 and 4 get short and produce beep sound on multimeter". The only way to perfrom a loopback test is to physically short Tx and Rx together so if you use a piece of wire to connect 2 and3, they will be shorted.

[Broken_Arrow]

Only thing that makes sense is maybe he means that when he shorts 2 and 3, on the other end of the cable, 3 and 4 are shorted, which means the cable has, um,  "special" wiring.

[sekhon]

Hi

          Thanks for helping me . Now my all 3 motors are in working condition. Problem get arised due to wrong use of usb to serial cable now i changed  cables and motors are sucessfully running..sir now i am going across a new problem i.e occuring in read operation .as i used flat structure to run motors in sequence . Thing which is happening is that sometime one motor give response and rest of two don't. sometime all  motors give response. so , please tell me which changes i do to come over it. 

[Vadim]

very treaky issue here, I have written a programm reading the info from two sensors using usb-rs232 converter and the drivers (at least I assume it's the drivers) are sometimes hanging up and causing my programm to hang.  Has anyone seen anything of this nature?