Channels A_ B Attenuator (Aa, Ba); Channels A. B Filter (Af. Bf); Channels A. B Impedance (Ai. Bi); Channels A; B Trigger Level (Al. Bl) - Keithley 776 Instruction Manual

AC1 = AC coupling channel A.
BCO = DC coupling channel B.
BCl = AC coupling channel B.
4-9-3. Channels A, B Attenuator (AA, BA)
The attenuator commands give the user control over the
input attenuator mode of channels A and B. The attenu-
ator may be programmed by sending one of the follow-
ing commands:
AA0 = xl attenuator channel A.
AA1 = xl0 attenuator channel A.
BAO
= xl attenuator channel
B.
BAI = x10 attenuator channel B.
4-94. Channels A, B Filter (AF, SF)
The filter commands give the user control over the filter
at Channels A and B input. The filter may be pro-
grammed by sending one of the following commands:
AFO = filter on channel A.
AFl = filter off channel A.
BFO = filter on channel B.
BFl = filter off channel B.
4-95. Channels A, B Slope (AS, BS)
The slope selection commands give the user control
over triggering edge at channels A and B inputs. The
slope may be programmed by sending one of the follow-
ing commands:
AS0 = Positive slope channel A.
AS1 = Negative slope channel A.
BSO = Positive slope channel B.
BSl = Negative slope channel B.
4-9-9. Channels A, B Impedance (Al, Bl)
The impedance selection commands give the user con-
trol over the input impedance at channels A and B
inputs. The impedance may be programmed b?; sending
one of the following commands:
AI0
= 1
MQ
impedance channel A.
AI1
= 50 R impedance channel A.
BIO
=
I MQ
impedance channel 8.
BIl
= 50 22 impedance channel B.
4-9-7. Channels A, B Trigger Level (AL, BL)
The trigger level commands give the user control over
the trigger threshold point at channels A and B inputs.
J-12
The trigger level may be programmed by sending one of
the following commands:
ALn = Trigger lewl channel A.
BLn = Trigger level channel B.
n is the trigger level in units of volts and in cnginccr-
ing format: e.g. (fD.DDiD). The sign and the csponcnt
are optional. The trigger level value may range from
-5.00 to +5.00 V in IO mV increments or from -50.0 to
+50.0 V in IOOmV incrcmenls. Selecting trigger Icvcl
wilbin the range of *S.OO V. automatically scls the
attenuator to xl. Selecting a trigger level within the
range of *SO.0 V. automatically modifies attenuator
selling to x10.
Following DCL or SDC commands. the instrument
defaults to ALO and BLO (trigger levels set to 0.00 V).
4-9-9. Channels A, B Auto trigger level (L)
The auto trigger level commands give the user control
over the auto trigger level mode. Auto-trigger mode is
automatically selected for both Channels A and B. The
aulo-trigger level mode may be programmed by sending
one of the following commands:
LO = Auto-trigger level disabled.
Ll = Auto-trigger level enabled.
4-98. Gate lime (G, GU)
The gate lime commands control the time that the gate
remains open. The gate time may be programmed by
sending command strings using the following formats:
Gnn = Internal gate time
GU = External user gate time
nn is the gate time in units of seconds and in engi-
neering format. e.g. (D.DE+D). Sign. decimal point. sod
exponent are optiooal.
The operator has the option or selecting an external
gate time having periods other then those programmed
into the instrument. The counter may be programmed to
accepl external gate times by sending the GU command
over the bus.
Following DCL or SDC. the instrument defaults to
gate time oi one second (G I .O).
4-g-10. Delay Time (IV, WU)
The delay time commands control the delay in closing
the gate after the gate was open. The delay time may be