Teledyne LeCroy X-STREAM OSCILLOSCOPES Remote Control User Manual
Page 12
P
A R T
O
N E
:
A B O U T
R E M O T E
C O N T R O L
6
ISSUED: February 2005
WM-RCM-E Rev D
PROGRAM MESSAGES
You control the oscilloscope remotely using program messages that consist of one or more commands or
queries. The program messages you send from the external controller to the X-Stream oscilloscope must
conform to precise format structures. The oscilloscope will execute all program messages sent in the correct
form, but will ignore those with errors.
You can use uppercase or lowercase characters, or both, in program messages; the scope does not distinguish
between them. But the MESSAGE command can faithfully transmit strings containing both lowercase and
uppercase letters.
Warning or error messages are normally not reported unless the controller explicitly examines the relevant status
register, or if the status-enable registers have been set so that the controller can be interrupted when an error
occurs. If you connect an external monitor to the instrument’s LAN port, however, you will be able to observe
all your remote control transactions, including error messages, as they happen. See the command
COMM_HELP in Part Two, “Commands.”
Program messages are separated by semicolons ; and end in a terminator:
The oscilloscope will not decode an incoming program message before receiving its terminator. The exception is
when the program message is longer than the 256 byte input buffer; then the oscilloscope will start analyzing the
message when the buffer is full. Commands and queries are executed in the order in which they are transmitted.
In GPIB mode, the following are valid terminators:
New Line character (i.e., the ASCII new-line character, whose decimal value is 10)
New Line character with a simultaneous
Signal together with the last character of the program message
The
N
N
O
O
T
T
E
E
:
: The
be set with a special call to the GPIB interface driver. Refer to the GPIB
interface manufacturer’s manual and support programs.
COMMANDS AND QUERIES
Program messages are made up of one or more commands or queries. While the command directs the
oscilloscope to change its state (for example, its timebase or vertical sensitivity) the query asks the oscilloscope
about that state. Very often, you will use the same characters for a command and a query, the query being
identified by a ? after the last character.
For example, to change the timebase to 2 ms/div, send this command to the oscilloscope:
TIME_DIV 2 M
Or, to ask the oscilloscope about its timebase, send this query: TIME_DIV?