HP E4418B Programming Manual page 169

MEASurement Instructions
FETCh[1|2][:SCALar][:POWer:AC]:RATio? [<expected_value>[,<resolution>[,<source list>]]]
1. The mnemonic
parameter used in the command sub-systems. The parameters must be entered in
the specified order. If parameters are omitted, they will default from the right.
The parameter DEFault is used as a place holder. Specifying
parameter value unchanged.
2. When the measurement result is linear this parameter represents the number
of significant digits. When the measurement result is logarithmic 1 to 4
represents a resolution of 1, 0.1, 0.01 and 0.001 respectively.
Example
Error Messages
If the last measurement on either channel is not valid error -230, "Data
corrupt or stale" occurs. A measurement is valid after it has been
initiated. It becomes invalid when either a reset occurs or any
measurement parameter, for example frequency, is changed.
If the resolution parameter is not the same as the current resolution
setting on the specified window, error -221, "Settings conflict" occurs.
2-32
Item Description/Default
source list This channel list specifies between
which channels the ratio is
calculated. If unspecified and the
current window setup is a ratio
measurement then this ratio setup
is used, otherwise it defaults to
channel A/B.
DEF means DEFault. This is not equivalent to the DEFault
FETC2:RAT? DEF,1,(@1),(@2)
Range of Values
(@1),(@2)
(@2),(@1)
DEF
This command queries the lower
window's ratio measurement of
channel A over channel B,
using the current sensor range
and a resolution of 1 on both
channels.
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