SEANHAWG 1 Posted January 4, 2012 I am trying to flash an IP camera that I bricked (by upgrading the wrong method) with new firmware. To make a long story short, The IP camera uses the same upgrade method as these DVR's that we use. So to test out first, I was going to try to upgrade a DVR that has a built in RS-232 port with the USB to RS-232 adapter and then move on to the IP camera once I get the method correct. Here is the problem I am facing. It appears that the DVR is receiving the transmission from the computer to the DVR, but the readout that I get back from the DVR to the computer just says "RXERR" For example, anytime I hit the enter button, I get an RXERR. And whenever I boot up the DVR, I get a bunch of RXERR. I assume this stands for "receiving error" So basically, the DVR is sending transmissions back to the DVR, but the program I am using is not displaying the readout. I am 100% confident that I am hooking everything up correctly and what not (Baud Rate, Correct Cables are crossed, Etc) and the manufacturer has claimed that it has worked for him and a few other customers. The only thing I can think of is the USB to RS-232 adapter I am using. I bought a couple, but they both seem to be using the Prolific PL-2303 chipset. I think this may be the problem. Does anyone have any indepth experience in these adapters. I have done a little research (and learned more then I care to know about RS-232) and it appears that some of these adapters have given problems for other people when using different applications. Share this post Link to post Share on other sites
tomcctv 190 Posted January 4, 2012 Hi Sean we use usb to rs232 for POS and we found it is always best to use a software based rs232. this then allows you to open and keep a com port. which is ideal for adding POS or PTZ via usb. we have been using moxa if you can wait 5 to 6 days i will send you one free to try. Share this post Link to post Share on other sites
SEANHAWG 1 Posted January 4, 2012 Thanks Tom. I have a couple of more adapters on order to see if that will work. If not, I will let you know. Share this post Link to post Share on other sites
Alik 0 Posted August 4, 2014 I have same problem like SEANHAWG with usb to rs232 adapter on ncom , how can i resolve it ? please help me . i tested with 3 different adapter Share this post Link to post Share on other sites
Billy_ICU 0 Posted August 6, 2014 Many RS-232 to USB adapters do not implement the RS-232 functions properly. For example the hardware "break" signal does not work. I spent $40 U.S. for a couple of different adapters which did not work, but the Parallax USB-RS232 adapter (much cheaper) works perfectly. (Does not look pretty, but it works.) The key is the use of FTDI chips and drivers (for those which work). Search google.com for... parallax usb-rs232 adapter Or here is a U.S. link... http://www.parallax.com/product/28030 Share this post Link to post Share on other sites
