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long (one digit for range and three digits for magnitude}.
If
more than four digits are sent to the 59501B, the desired out-
put voltage will not appear at the output.
3-23
Unipolar Mode
3-24
Low Range. The desired
59501B output voltage
values are from 0 to 0.999V programmable in 999 steps.
The resolution in this range is equal to .999V/999, or 1mV
per step. To calculate the correct data word value to pro-
duce the desired output within this range, proceed as
follows:
l
1. The resolution in the low range is 1mV,
Let D = .001
2. The range digit is 1 for the low range, so add 1
to the left of the 3 magnitude digits,
Let R = 1000
. 3. The magnitude portion (M) is calculated by
dividing the desired output voltage (V) by the
least significant digit D. The magnitude portion
must be rounded off to exactly 3 digits,
= INT (V/D + 0.5) = 3 magnitude digits
4, Combine range and rounded off magnitude
portion to obtain the correct data word value (N),
N=R+M
Example, desired voltage = 0.5123V
um = 001
= 1000
4 = INT (0.5123/.001 + 0.5)
M = INT (512.8)
N = 1000 + 512
N = 1512 = data word value -
In this example, the desired output voltage is 0.5123 volts
but the actual output is 0.512V because the resolution is
1mV (least significant digit equals .001):
V=MxD
V = 512 x .001
V= 6,512
3-25
High Range. The desired
59501B output voltage
values are from 0 to 9.99V.
The calculations are the same
as for the low range, except resolution is 10mV and the
high range is used.
For the high range,
Let D = 01
and R = 2000
3-26
Bipolar Mode `-
3-27
Low Range.
The desired
59501B output voltage
values are from —1V to *0.998V programmable in 999
steps.
For a —1V output, the magnitude digits are 000 and
for a *0.998V output, the magnitude digits are 999.
A OV
output is obtained when the magnitude digits are 500.
Resolution in this range is equal to 1.998/999, or 2mV.
To
calculate the correct data word value to produce the desired
3-3
positive or negative output voltage within this range, pro-
ceed as follows:
1. The resolution in thé —1V to 0.998V range is ens
Let D= .002
2. The range digit is 1 for the low range, so add 1
to the left of the three magnitude digits,
Let R = 1000
3. The magnitude portion (M) is calculated by `
adding 1 to the desired negative or positive out-
put voltage (V) and dividing this sum by the least
sighificant digit D. The magnitude portion must
be rounded off to exactly 3 digits.
MzINT(V-1V/D*0.5)
-
4. Combine range and rounded off magnitude pot-
tion to obtain the correct data word value {N},
N=R+M
' Example, desired voltage = —0.5123V
x = 002
= 1000
.
= INT
(—5.123 + 1)/.002 + 0.5)
= INT (243.85 + 0.5)
= INT (244.35)
= 1000 + 244 = 1244
|
in this example, the de
output voltage is —0.5123V
but the actual output is --0.512V because the resolution is
2mV (.002):
C
= INT (40.4877/.002 + 0.5)
(
(
V= (Mx D) --1
V = (244 x ,.002) — 1
V = 0.488 — 1
V = —0.512V
3-28
High Range. The desired output voltage values are
from —10V to +9.98V.
Calculations are similar to those
for the low range, except resolution is 20mV on the high
range, and 10 must be added to desired positive or negative
output voltage in order tó calculate the correct magnitude
digits.
For this range, the equation for the magnitude
portion (M) of the data word value is:
M = INT ((V + 10)/D + 0.5)
Example, desired voltage = —5.123V
D= 02
R = 2000
M = INT ((—5.123 + 10)/D + 0.5)
M = INT (243.85 + 0.5)
M = INT (244,35) = 244
N = 2000 + 244 = 2244
in this example, ie desired output voltage is —5.123V but
the actual output is —5.12V because the resolution is 20mV -
(.002):
V - (M x D) —10
V = (244 x .02) — 10
V = 4,88 — 10
V = —5,12V
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