R Output; Output Channel 1; Rel Channel 1; Offset Channel 1 - Stanford Research Systems SR530 Manual

display CH1
setting output expand? offset? (RCOSØ)
X X+X ofst yes
XOFST X ofst yes
R R+R ofst yes
R OFST R ofst yes
XNOISE X noise yes
X5 X5 no
The EXPAND and OFFSET conditions for each
display are retained when the DISPLAY is
changed. Thus, when the DISPLAY is changed
from X to R, the EXPAND and OFFSET assume
the conditions set the last time the DISPLAY was
R. If the DISPLAY is changed back to X, the
EXPAND and OFFSET return to conditions set for
X.

R Output

The magnitude, R, is given by the equation:
R = {(X+X ofst ) 2 + (Y+Y ofst ) 2 } 1/2 + R ofst
Note that the X and Y offsets affect the value of R
while the X and Y expands do not.
The magnitude output has a resolution of 12 bits
plus sign and is updated every 3.5 mS. To
achieve maximum accuracy, the magnitude should
be as large a fraction of full scale as possible.
R is expanded after the calculation. Thus, when R
is expanded, the full scale resolution drops by a
factor of 10 to about 9 bits.

Output Channel 1

The CHANNEL 1 output is available at the left
hand OUTPUT BNC connector. The output
parameter is selected by the DISPLAY setting and
can be X, X OFST, R (magnitude), R OFST, X
NOISE, or X5 (external D/A). (Note that X5 is the
ratio output at power up. When displaying X5, the
ratio output is 10R/X1). All outputs are ±10V full
scale when the EXPAND is off. With the EXPAND
on, the output is multipled by 10 effectively
increasing the full scale sensitivity by 10. (X5 may
not be expanded). The output impedance is < 1Ω
and the output current is limited to 20 mA.
X
yes X+X ofst
yes X ofst
yes X+X ofst
yes X+X ofst
yes X+X ofst (enbw)
adjust X+X ofst
The left hand analog meter always displays the
CHANNEL 1 OUTPUT voltage. Accuracy is 2% of
full scale.
The CHANNEL 1 LCD display provides a read-out
of the displayed parameter in real units. The scale
of the displayed quantity is indicated by the three
scale LED's to the left of the display. This read-
out auto ranges and will reflect the sensitivity
added when the EXPAND function is on. When
displaying X5, the scale LED's are off and the
units are volts.

Rel Channel 1

Every time the REL key is pressed, the displayed
parameter is offset to zero. This is done by
loading the displayed parameter's offset with
minus one times the present output. If the output
is greater than 1.024 times full scale, the REL
function will not be able to zero the output. In this
case, the OFFSET ON LED will blink and the
offset value will be set to its maximum value.
The REL function and the manual OFFSET are
both ways to enter the offset value. After using
the REL key, the offset may be adjusted using the
manual OFFSET.
When the DISPLAY is X, X OFST, or X NOISE,
the REL key sets the X OFFSET (which affects
the X (RCOSØ) output). If X NOISE is being
displayed, the REL function zeroes X and the
noise output will require a few seconds to settle
again.
When the DISPLAY is R or R OFST, the REL key
sets the R OFFSET.
The REL key zeroes the X5 output when the
DISPLAY is D/A.

Offset Channel 1

The OFFSET buttons control the manual offset.
The offset is turned ON and OFF using the upper
key in the OFFSET section. When the offset is
ON, the lower two keys are used to set the amount
of offset. A single key press will advance the
offset by 0.025% of full scale. If the key is held
down, the offset advances in larger and larger
increments, the largest increment being 10% of full
scale. When the offset is turned OFF the applied
offset returns to zero but the offset value is not
lost. The next press of the upper offset key (return
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