I need to know the Pelco D/P Protocol. I would like to write a sw for control my PTZ camera with a RS485 Pelco D/P protocol drives. Any comments will be appreciated.
Thanks.
D Protocol is a type serial protocol of sending/receiving data from the controller to camera for the pan /tilt and zoom functions. In D protocol separate data cable is required rather than the cable for video.
P Protocol is a type of superimposing the data signal over the video signal in the same cable (i.e. in case of coaxial cable transmission same coaxial cable will be used to carry the data signal along with the video without additional cables).
Here's a link to a site I found with both Pelco P and D protocols. They also have a Windows based control panel and a great (free) Debugging tool that shows the code you are sending to the Pelco Device.
Try this website: http://www.rs232analyzer.com, they provide in depth explanation and example of Pelco D/P protocol and the free terminal to play with Pelco D/P PTZ cameras.
You are right about D Protocol but P and D are similar, both needing a separate control wire. What you think P Protocol is actually is called Coaxitron. Coaxitron sends the control over the coaxial cable. D and P differ on baud rates and max units able to control but are pretty similar. Coaxitron control needs both a coaxitron able camera plus a coaxitron able controller like a CXT or a MXB with coaxitron capability. Pelco's new network video recording system Endura also uses coaxitron. As you can probably tell Coaxitron is a Pelco thing, i'm not sure if any other manufacturer uses it. The only road block with it is that it can't send control through any active transmission system like a Signal Amplifier or a Powered UTP unit. Hope this helps.
To get more info about the Pelco D protocol, just get the spec for it from Pelco. If you email [email protected] with your name, company, address (real and email) along with your application, they will send you the spec.
I have a system with 2 PTZ cameras, 2 DVRs and a non Pelco keyboard. Is there a way that I can have one of the PTZ go to a preset at 2pm every day for 10 min and then return to its home.
I've integrated in a C# program the class Pelco D and Pelco P; as most I've read, they don't work: fault is the calculation of the checksum which uses ^(Xor) instead of + (Plus /Or).