Stanford Research Systems SR844, User Manual

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4-10 Remote Operation
SR844 RF Lock-In Amplifier
Command Syntax
The four letter mnemonic (shown in CAPS) in each command sequence specifies the
command. The rest of the sequence consists of parameters. Parameters shown in { } and
[ ] are not always required. Generally, parameters in { } are required to set a value in the
SR844 and parameters in [ ] are optional in both set and query commands. Multiple
parameters are separated by commas. Multiple commands may be sent on one command
line by separating them with semicolons (;).
The present value of a parameter may be determined by sending a query command.
Commands that may be queried have a question mark in parentheses (?) after the
mnemonic. Commands that may ONLY be queried have a ? after the mnemonic.
Commands that MAY NOT be queried have no ?. A query is formed by including the
question mark ? after the command mnemonic and omitting the queried parameter from
the command. The query parameters shown in { } are NOT sent with a query. The query
returns the value of these parameters. Values are returned as a string of ASCII characters
(unless otherwise noted).
Do not send ( ) or { } or [ ] as part of the command.
For example, the command
AUXO (?) i {,x}
is used as follows.
AUXO 1,1.234
Set AUX OUT 1 to 1.234 V
AUXO? 1
Query the current setting of AUX OUT 1
Variables are defined as follows.
ch
output channel (1=CH1, 2=CH2)
i,j,k,l,m,n,q
integers
x,y,z
real numbers
f
real number frequency in Hz
s
text string
All numeric variables may be expressed in integer, floating point or exponential formats
(i.e., the number five can be either
5, 5.0,
or
0.5E1
). Strings are sent as a sequence
of ASCII characters.
Output Interface (RS232 or GPIB)
All responses are directed only to the selected output interface. Use the OUTX
command at the beginning of every program to select the correct interface.