Numb-nuts 1 Posted July 12, 2011 I have been looking at DVR cards, but I cannot see how the alarm inputs are connected and the specs rarely mention alarm inputs / outputs. Would I be right in assuming that most DVR cards don't support alarm inputs? If they do, where are these connected usually and how does one connect a PTZ controller as they don't seem to have RS485 terminals either. I know they support RS485 through their software but I prefer adding a hardware controller. I have heard people talking about RS485 to RS-232 coversion cards but don't understand about these do they just plug in and thats it or do they require drivers. I have heard a few posts where these tend not to work too well? I would be grateful if someone could describe how DVR cards are connected, obviously I have seen them with BNC and audio inputs outputs either on the card or on plug in leads, but that seems to be it. no other connections. Anticipating your advice and comments, thanks. Share this post Link to post Share on other sites
tomcctv 190 Posted July 12, 2011 alot of the time its possable to use USB ports and use coverters. best using converters with drivers if you want to assign com ports. USB to RS232 USB to RS232 then RS485 RS232 to RS 485 all of which can also connect PTZ or alarm I/O boxes (alarms) I/O alarm box. Share this post Link to post Share on other sites
rory 0 Posted July 12, 2011 Most DVR Cards have alarm input cards or separate devices as an option. Share this post Link to post Share on other sites
Numb-nuts 1 Posted July 15, 2011 Most DVR Cards have alarm input cards or separate devices as an option. I've obviously been looking in the wrong places. I will make some more enquiries about these add on cards. Share this post Link to post Share on other sites
Soundy 1 Posted July 16, 2011 I would be grateful if someone could describe how DVR cards are connected... You'll have to be a little more specific than that, because there are literally thousands of DVR card designs out there, and not all of them work the same way. As the others have said, most will use either an existing serial port, or some sort of add-on card. Some software can also use external USB or network-attached I/O devices, like this: That's a function of the software, though, not the card itself. Share this post Link to post Share on other sites
