fixitbaz 0 Posted March 31, 2009 Hi I have a Ademco AHDR9 DVDR and have 6 fixed cameras plugged into it they are all working fine. I am interested in setting up a PTZ dome on the DVDR but unsure on the wire connections for the RS485 on the back of the unit. It has 4 terminals marked up as follows RX+ RX- TX+ TX- The camera I am trying to connect only has RS485 +,- Do I connect the RX+ & TX+ of the DVDR to the RS485 + of the camera RX- & TX- of the DVDR to the RS485 - of the camera Also would I be able to use a 8 core screened alarm cable to carry the RS485 signal and video between the DVDR and camera. or would I need to run a new cat 5 twised pair cable????? Any help would be great as I am new to all this. Cheers Barry Share this post Link to post Share on other sites
coolie11 0 Posted March 31, 2009 DVR Camera TX+ ----------------- RX+ TX- ----------------- RX- You can use 18Awg to 24Awg Cable. Share this post Link to post Share on other sites
Soundy 1 Posted April 1, 2009 You need only a single pair of wire to carry your control signal. Connect the TX+ on the DVR to the 485+ on the camera; TX- to 485-. Leave the RX connections alone. There are a few options for wiring... Cat5 will do, but it's overkill if ALL you're running over it is serial control. What I've done in situations like this, is to use Cat5, with one pair for video (with baluns), one pair for serial control, and the two remaining pairs for power. My usual color scheme is blue pair for video (blue for tip, blue/white for ring), brown for control (brown for +, white/brown for -), and the orange+orange/white pair together for one side of the power (+12V for DC) and green+green/white for the other. Aside from that, just about any single pair of wire will do - speaker wire, microphone wire, station wire, Cat3, etc. Twisted-pair is better for longer distances, but up to couple hundred feet, it's probably not necessary. Share this post Link to post Share on other sites
fixitbaz 0 Posted April 1, 2009 Thanks for your help one more bit of info please Is there anyway in checking the RS485 outputs on the back of the DVDR as I have connected it to the PTZ unit but it does nothing. The PTZ unit is one of the middle east units that are listed on fleabay everwhere I was given this unit so if this works the better for me. It might be this unit faulty but before buying a better unit is there anyway in checking the DVDR outputs Cheers Barry Share this post Link to post Share on other sites
shoreviewsecurity 0 Posted April 1, 2009 Hi Barry, Depending upon the DVR, you can measure the voltage off the RS-485 Terminals. I have found it to be around 5VDC in the neutral position. May be a different voltage with your DVR though???? Hope this helps Mike Share this post Link to post Share on other sites
survtech 0 Posted April 2, 2009 Make sure both the DVR and the PTZ are set to the same protocol, bit rate and communications configuration. The most common is Pelco "D" protocol, 2400 or 4800 baud, no parity, 8 data bits and 1 stop bit. Share this post Link to post Share on other sites
Soundy 1 Posted April 2, 2009 Some PTZs, when you start them up, will display the baud rate, protocol, and/or camera ID they're set for... watch for it when powering up. Camera ID must match as well. Share this post Link to post Share on other sites
