PELCO-P内部Protocol.doc

PELCO P PROTOCOL GENERAL This section describes the protocol used when sending commands to an Intercept Dome in the “P” version protocol. The protocol uses no parity, one start bit, eight data bits, and one stop bit. The recommended baud rate is 4800 (4800, 8, N, 1, 1). MESSAGE FORMAT Byte Value Function 1 $A0 STX (start transmission) 2 $00 to $1F Address 3 Data byte 1 (see below) 4 Data byte 2 (see below) 5 Data byte 3 (see below) 6 Data byte 4 (see below) 7 $AF ETX (end transmission) 8 $00-$FF Check Sum Byte 1 is always $A0 Byte 2 is the receiver address, set by DIP switch in the receiver Byte 3-6, see below Byte 7 is always $AF Byte 8 is an XOR sum of Bytes 1-7 The protocol is “zero indexed” so that the hexadecimal address sent in the protocol for the first receiver is $00 which corresponds to address 1. The bits within the “Data bytes” are broken up into two main groups. For Pan and Tilt commands, the functions are determined as follows: PAN AND TILT COMMANDS Bit number 7 6 5 4 3 2 1 0 Data 1 0 0 0 0 Iris Close Iris Open Focus Near Focus Far Data 2 0 Zoom Wide Zoom Tele Tilt Down Tilt Up Pan Left Pan Right 0 (for pan / tilt) Data 3 Pan Speed $00 to $3F and $40 for Turbo Data 4 Tilt Speed $00 to $3F EXTENDED COMMAND SET The extended command set will have bit 0 of data byte 2 set and will follow the format in the following table: Command Data byte 1 Data byte 2 Data byte 3 Data byte 4 Set Preset XX 00 03 00 00 to 7F Clear Preset XX 00 05 00 00 to 7F Go To Preset XX 00 07 00 00 to 7F AUX ON 00 09 00 0-8 AUX OFF 00 0B 00 0-8 Flip (rotate 180o) 00 0D 00 0 FLIP（90度） 00 0D 00 1 Zero Pan Position 00 0D 00 2 Begin Random scan 00 0D 00 3 Begin Frame Scan 00 0D 00 4 Begin Auto-Scan 00 0D 00 5 Stop Scan 00 0D 00 6 Remote Reset 00 0F 00 00 Zone Start 00 11 00 01 to 08 Zone End 00 13 00 01 to 08 Write char to screen 00 15 0 to 28 0 to 7F Clear Screen 00 17 00 00 Alarm Ack 00 19 00 01 to 08 Zone Scan On 00 1B 00 00 Zone Scan Off