Camera RS232 Protocols

I am looking for information on camera RS232/RS485 protocols. The camera I have lists its supported protocols as:

1. Pelco D
2. Pelco P
3. Fastrax
4. Command

I don't think that Pelco has the features I need but I can't find any information o开发者_StackOverflown the last two. Pelco only appears to allow differential changing of zoom and focus (commands to move in/out from current position) but I need to be able to actually SET a value say between 0 and 65535, and also READ the current value.

In fact, I would purchase a completely new camera if I knew it would support the features I need at an afforable (

Any more knowledgeable programmers have some advice on these protocols?

Default Pelco protocol definition does not appear to support this feature. Contacting vendors directly will sometimes help as different vendors will implement custom protocols. However, there does not appear to be a unified definition anywhere to get/set camera positions.