Tandberg Data 1080P User Manual

Page of 29
D14640.01—MARCH 2010 
21
TANDBERG PrecisionHD 1080p/720p camera
Camera User Guide
Contents
Introduction
Physical interface
Cables
Connecti to codec
Video formats
Daisy chaining
Appendices
Contact us
www.tandberg.com
The VISCA™/RS–232 
control protocol
When interfacing to the PrecisionHD 12X/4X 
1080p, the codec uses an RS-232 control 
interface that resembles the Sony VISCA™ 
protocol.
VISCA message format
A particular command is recognized by the 
message information after the address byte.
Message Format
Commands are initiated from the host (i.e. the 
codec or any other external controller) to the 
camera.
After a camera has been issued a command, 
the camera will generate a response. 
Commands and responses (messages) have the 
following format:
• 
Address byte (1)
• 
Message bytes (1..14)
• 
Terminator byte (1)
See the illustration for details.
The minimum length of any command or response is 3 bytes:
1.  Address byte (1):
 Let us assume there is one host, i.e. the codec (the host is the unit controlling 
the camera). The host has address 0. The four least significant bits of the address byte contain the 
address of the receiver. In the case of a broadcast message, the receiver address must be set to 
8. When we are operating a single camera, the address is 1. Hence, address bytes in messages 
from the host are 0x81, and messages from the camera to the host are 0x90 (the protocol allows 
for up to 7 cameras).
2.  Message bytes (1..14):
 Any number of bytes containing the actual message information. Bytes 
may have any value in the range 0...254. The value 255 (i.e. hexadecimal FF) is reserved for the 
terminating byte.
3.  Terminator byte (1):
 All messages must be terminated with a byte containing all 1’s, i.e. decimal 
255 (or hexadecimal FF).
Command and response exchange
When the camera receives a command, it 
responds with either:
• 
Completion message: 90-5Y-FF   
Returned by camera when execution of 
commands and inquiries are completed.
• 
Error packets: 90-6Y-..-FF 
 
Returned by camera instead of a completion 
message when command or inquiry failed to 
be executed.
General error messages, unless otherwise 
specified:
• 
90-6Y-01-FF Message length error 
(>14 bytes)
• 
90-6Y-02-FF Syntax error
• 
90-6Y-03-FF Command buffer full
• 
90-6Y-04-FF Command cancelled
• 
90-6Y-05-FF No socket (to be cancelled)
• 
90-6Y-41-FF Command not executable
• 
Y = socket number
A camera may contain two buffers so that 
two commands, including the command 
being executed, can be received. 
NOTE:
 The PrecisionHD 1080p camera 
supports a single socket only. Consequently, 
the Y always assumes the value 
Y = 0
.
Exceptions to these rules:
• 
An Initialize message will respond as 
indicated in the Table of Commands (this 
message is in fact a broadcast message, 
and any unit other than the host receiving the 
broadcast message must pass it on).
• 
Do not route commands or replies that are 
longer than 16 bytes through Sony cameras. 
The easiest way to avoid this is to put the 
TANDBERG cameras first in the chain. 
Commands and replies that are longer than 
16 bytes are clearly marked below.
The RS232 Message format
...
Sender’s 
address
Receiver’s 
address
1                   0
LSB
Packet (3 to 16 bytes)
Message (1 to 14 bytes)
Address
Byte 1         Byte 2         Byte 3
Terminator
FF
1   1   1   1   1   1   1   1
LSB
Contact us
Contents
Introduction
Cables
Daisy chaining
Appendices
Physical interface
Connect to codec
Video formats
Appendices