Have captured some of the commands sent by the NightOwl Posiedon DVR security system.  Sent via RS485 to the camera's.  Will show the command, and the Oscilloscope will show the signal and its decoded Hex format (using a Tektronix Scope with the DPOCOMP module:)
Signals:
The Osciloscope is a Tektronix MSO4054 (Mixed Signal, 500MHz, 4 channel scope) with the capabilities to decode the serial stream.  Cyan trace is +", the Blue trace is "-", and the violet is the scopes decode of the serial stream.  At the lower left are several "automatic" measurements made on the signal.

I have noticed that the signal levels appear pretty low.  The two devices are connected via 2 wire, and a ground so this is in Half Duplex mode.

I will add an caption to each showing what the sent signal should have been....

RS485 Communicatoin between a Pelco-D camera and Poisidon DVR Controller

		STX	ID	Data1	Data 2	Data 3	Data 4	ETX	(XOR)
Sig #	Description	Byte 1	Byte 2	Byte 3	Byte 4	Byte 5	Byte 6	Byte 7	Byte 8	Comment ?
1	Default?	A0	01	00	07	00	02	AF	0B
2	Tilt UP	A0	01	00	08	00	15	AF	13	Tilt Up, Tilt Speed 15
3	Tilt Down	A0	01	00	10	00	00	AF	0B	Tilt Down;
4	Pan Right	A0	01	00	02	15	00	AF	19	Pan Right,Pan Speed 15
5	Pan Left	A0	01	00	04	00	00	AF	0A	Pan-Left
6	Speed Low	A0	01	00	07	00	02	AF	0B	Iris Open, Focus Near, Focus Far, Tilt Speed 02
7	Speed Hi	A0	01	00	07	00	01	AF	08	Iris Open, Focus Near, Focus Far, Tilt Speed 01
8	Zoom +	A0	01	00	20	00	00	AF	2E	Zoom Tele
9	Zoom -	A0	01	00	40	00	00	AF	4E	Zoom Wide
10	Focus +	A0	01	01	00	00	00	AF	OE	Focus Far
11	Focus -	A0	01	02	00	00	00	AF	OC	Focus Near
12	Iris +	A0	01	04	00	00	00	AF	OA	Iris Open
13	Iris -	A0	01	08	00	00	00	AF	06	Iris Close
14	Goto Pos 5	A0	01	00	00	00	05	AF	0C	Tilt Speed 05
15	Goto Pos 2	A0	01	00	07	00	02	AF	00	Iris Open, Focus Near, Focus Far, Tilt Speed 02
16	Cruize	A0	01	00	07	00	02	AF	OB	Iris Open, Focus Near, Focus Far, Tilt Speed 02
17	Pan Top-Rgt	FF	03	00	OA	15	15	37	00	What happened Here????
Setup:  PTZ, Pelco-P, ID=1;  Serial Rate: 9600,8,N,1;
First Byte for Pelco-P is always AO, 2nd byte is address 01