EXFO T200S, User Manual, Page: 57 / 146

Remotely Controlling the T200S
Tunable Laser Source
51
Communication Principle
There are also several conventions regarding command syntax:
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Spelling errors cancel the command or query.
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The unit of received numerical values is always the base unit.
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Numerical values are entered in decimal format.
Result format for float is +1.12345678E-123.
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If a transmitted value has a higher precision than expected, the value is rounded off to
the nearest accepted value.
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Commands and queries are not case-sensitive. You can type your program messages
using either lower-case or upper-case letters.
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The command or query can be written using only the three- or four-letter shortcuts,
only full words, or a combination of both.
The example below shows the long and the short forms of a same query.
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A message must end with the following characters: CR LF (\r \n)
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The T200S uses the ISO-8859-1:1998 (Latin-1, West Europe) character set. Make sure to
configure your remote client with the same character set and to use supported
characters while giving names to files or to other items.
Command Types
The T200S uses the following types of commands and queries:
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Sequential: these commands are executed one after the other, in sequential order. A
sequential command always finishes before the next command is implemented.
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Overlapped: these commands allow execution of overlapping commands while
execution of the overlapped commands is still in progress.
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Overlapping: these commands can be executed during execution of an overlapped
command.
;
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Mandatory to separate the different commands of a program message
when more than one command is sent at a time.
If an error occurs in a command of a program message, the program
does not stop: all the commands of the program message are still
executed.
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Also used to separate responses when multiple queries were sent in a
single program message
.
,
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Mandatory to separate parameters in a command or a query.
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Also used to separate the various responses from a query.
Item Meaning
:SYSTem:ERRor?
:SYST:ERR?
:syst:err?
Long form
Short form (small words
represented by the capital letters
of the long form)