Ametek 7270 - Page 205

Appendix E, ALPHABETICAL LISTING OF COMMANDS
E-13
FSTEP[.] [n
1
n
2
] Oscillator frequency sweep step size and type
The frequency may be swept either linearly or logarithmically, as specified by
parameter n
2
. The step size is specified by parameter n
1
.
Log sweep n
2
= 0
In fixed point mode, n
1
is the step size in thousandths of a percent.
In floating point mode n
1
is in percent. The range of n
1
is 0 to 100.000%
Linear sweep n
2
= 1
In fixed point mode, n
1
is the step size in millihertz.
In floating point mode n
1
is in hertz. The range of n
1
is 0 to 250 kHz
Linear seek sweep n
2
= 2
In fixed point mode, n
1
is the step size in millihertz.
In floating point mode n
1
is in hertz. The range of n
1
is 0 to 250 kHz
The seek sweep mode automatically stops when the signal magnitude exceeds
50% of full scale. This mode is most commonly used when setting up the virtual
reference mode.
FSTOP[.] [n] Oscillator frequency sweep stop frequency
Sets the stop frequency for a subsequent sweep of the internal oscillator frequency,
in the range 0 to 250 kHz.
In fixed point mode, n is in millihertz and in floating point mode n is in hertz.
HC Halt curve acquisition
Halts curve acquisition in progress. It is effective during both single (data acquisition
initiated by TD command) and continuous (data acquisition initiated by TDC
command) curve acquisitions. The curve may be restarted by means of the TD, TDT
or TDC command, as appropriate. If an oscillator frequency and/or amplitude sweep
has been defined and linked to the curve buffer using the SWEEP command with a
parameter of 9, 10 or 100, then this sweep will be stopped as well.
ID Identification
Causes the lock-in amplifier to respond with the number 7270.
IE [n] Reference channel source control (Internal/External)
In Single Reference and Dual Harmonic mode, the value of n sets the reference input
mode according to the following table:
n Selection
0 INT (internal)
1 EXT (external rear panel TTLREF IN input)
2 EXT (external front panel analog REF input)
This command is invalid in Dual Reference mode
IE1 [n] Reference channel 1 source control, Dual Reference
In Dual Reference mode, the value of n sets the reference channel 1 source according
to the following table: