Remote Interface
ProTelevision Technologies
PT 5780 DVB-T Modulator
Instruction Manual
Revision 3.11
5-2
5.2.2
Syntax of Program Messages
A command or query command is called a program message unit. Such a program message
unit consists of a header or a header separated by a space from one or more parameters. The
program header separator between the header and the first parameter must be at least one
“white space” character. The header consists of one or more mnemonics (key words) describing
the command. The parameters in a message unit are also referred to as “Data Elements”. They
are mutually separated by a comma (,), which is referred to as “Data Separator”. Furthermore
the following rules are valid:
♦
Any one of the “white space” characters (decimal values 0..9, 11.. 32) may:
−
precede a header
−
precede the Message Terminator
−
be placed in between the header and the parameter
−
be placed in between two consecutive parameters
♦
String data in a parameter must be specified between quotes. A quote may either be an
ASCII “single quote” (decimal 39) or an ASCII “double quote” character (decimal 34)
♦
One or more program message units (commands) may be sent within a single program
message. Program message units are separated by a semicolon (;). A message of one or
more units is terminated by a program message terminator
♦
The program message terminator must be the following code:
−
LF <line feed> (decimal10) code
Basically there are two types of program headers:
♦
Compound headers
Commands have a compound header consisting of one of more key words (mnemonics),
mutually separated by a colon (:) character. Such as a colon may also precede the header
♦
Command headers
The program messages that are standardized are called common commands. Their headers
always start with an asterisk (*) character
Each keyword in a compound command header represents a node in the command tree. The
left most key word is the root node, representing the highest hierarchical level in the command
tree. Subsequent keywords represent sub nodes under the root node.
5.2.3
Syntax of Response Messages
The response to a query command is a response message unit, consisting of one or more
parameters (data elements). Successive parameters are separated by a comma (,). All
command queries end with a question mark (?), with no space between the command header
and the question mark. If a parameter is required in a query command, it is placed after the
question with a space between the two, for example:
SYST:PRES:NAME? 2
where this command requests the name of preset number 2.
If there are multiple queries in a program message, the multiple response message units are
grouped together in the corresponding response message.
Response message units are separated by a semicolon (;) and are terminated by a response
message terminator.
Summary of Contents for PT 5780
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