Stanford Research Systems SR830, Manual

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4-26
Front Panel
WARNING MESSAGES
The SR830 displays various warning messages whenever the operation of the instrument is not obvious. The
two tone warning alarm sounds when these messages are displayed.
Display Warning Message Meaning
LOCL LOut LOCAL LOCKOUT If the computer interface has placed the unit in the REMOTE
state, indicated by the REMOTE led, then the keys and the knob
are disabled. Attempts to change the settings from the front
panel will display this message.
IGAn chG IGAIN CHANGE Indicates that the current conversion gain has been changed to
1 M
Ω
as a result of changing the sensitivity. Sensitivities from
20 nA to 1 µA require 1 M
Ω
current gain.
tc chnG TC CHANGE Indicates that the time constant has been changed, either by
increasing the detection frequency from below 200 Hz to above
200 Hz, or by changing the sensitivity, dynamic reserve, filter
slope, or expand.
hAr ovEr HARMONIC OVER An attempt to increase the harmonic detect frequency above
102 kHz will display this message.
tc ovEr TC OVER Indicates that the time constant is too long (>1s) for Auto Gain to
run.
PhAS bAd PHASE BAD Indicates that the phase is unstable and Auto Phase will not run.
rcal dAtA Err RECALL DATA ERR This message is displayed if the recalled setup is not valid. This
is usually because a setup has never been saved into the select-
ed buffer.
undr UNDR Indicates unit may not be precisely locked at very low frequency.