bigbrickhouse 0 Posted February 21, 2009 How can I test a DVR's protocol outputs without a PTZ cam? The install has a Speco 4 Channel DVR. I put in two Pelco PTZ platforms and an aftermarket PTZ receiver driver for each. The receiver's language is Pelco D. The DVR has Pelco D protocol but I'm not getting any reaction out of the receiver/drivers when commanded to move. I've tested all wiring as well as all available baud rates in the DVR. The receiver manufacturer recommended taking a known working PTZ controller with Pelco D to test the receivers which they claimed they've never had problems with. The install is 400 miles away and I need to diagnose it on the weekend when little or no tech support is handy. I'm doubting that two brand new receivers would be DOA. The SPECO dvr was not part of my install but is only 8 monthes old since new. Any insight as to a way of testing the DVR's Pelco D control output without a PTZ cam and any other insight as to what could be going wrong would be appreciated. Share this post Link to post Share on other sites
Soundy 1 Posted February 21, 2009 I use a USB-to-serial adapter on my laptop, and HyperTerminal (yeah, just the little basic terminal bundled with Windows), to view incoming serial data. I made an "adapter" using a DB-9F solder-on connector, with short wires to pins 2 (TX), 3 (RX), and 5 (ground), and small alligator clips on the other end. In this case, you'd connect pins 3 and 5 on such an adapter to the wires from your DVR, set your baud rate and protocols to match the DVR's serial ports (probably 2400 or 9600, 8N1, no flow control), and fire up HyperTerm connected to the USB serial port.... then start driving the PTZ controls on the DVR and watch for garbage to show up on HyperTerm. If you want to get more in-depth, you can use serial capture/analysis software to see what data the DVR is actually sending... this package, for example, even includes a tutorial on their web page for reading and understanding the control codes it's seeing: http://www.232analyzer.com/RS232_Examples/CCTV/Pelco_D_Pelco_P_Examples_Tutorial.HTM Finally, if you're using RS-232 (vs. RS-422 or 485), there's a little trick I've found works sometimes: with the camera off, connect the wires with the proper polarity, then fire up the camera, and switch the wires (so the GND wire on the DVR goes to the RX+ input on the camera, and pin 2 on the DVR goes to the RX- on the camera). Often, it will just start working after that! Share this post Link to post Share on other sites
