Specifications

A typical use of this function would be to output an analog voltage or current at
each Scan Trigger of the VT1419A and over the range of the haversine. For
example, suppose a new position of an analog output to move from 1 mA to 3 mA
over a period of 100 ms is required. If the TRIG:TIMER setting or the EXTernal
trigger was set to 2 ms, then force fifty intervals over the range of the haversine.
This can be easily done by using a scalar variable to count the number of times the
algorithm has executed and to scale the variable value to the -p/2 to p /2 range.
3 mA is multiplied times the custom function result over each interval which will
yield the shape of the haversine
()
0003 0001.sin .´+x
.
Try the “eufn1419.vee” example program and define some custom functions to
illustrate this discussion.
Table 1 shows some examples of the accuracy of the custom function with various
input values compared to an evaluation of the actual transcendental function found
in ‘C’ or RMB. Please note that the Mx+B segments are located on boundaries
specified by 2/64 on each side ofX=0. This means that if the exact input value is
selected that was used for the beginning of each segment, the exact
value of the
function at that point will be calculated. Any point between segments will be an
approximation dependent upon the linearity of that segment. Also note that values
ofX=2andX=-2will result in Y = infinity.
‘C’ sin(-1.570798) -1.000000 ‘VT1419A’ sin(-1.570798) -0.999905
‘C’ sin(-1.256639) -0.951057 ‘VT1419A’ sin(-1.256639) -0.950965
‘C’ sin(-0.942479) -0.809018 ‘VT1419A’ sin(-0.942479) -0.808944
‘C’ sin(-0.628319) -0.587786 ‘VT1419A’ sin(-0.628319) -0.587740
‘C’ sin(-0.314160) -0.309017 ‘VT1419A’ sin(-0.314160) -0.308998
‘C’ sin(0.000000) 0.000000 ‘VT1419A’ sin(0.000000) 0.000000
‘C’ sin(0.314160) 0.309017 ‘VT1419A’ sin(0.314160) 0.308998
‘C’ sin(0.628319) 0.587786 ‘VT1419A’ sin(0.628319) 0.587740
‘C’ sin(0.942479) 0.809018 ‘VT1419A’ sin(0.942479) 0.808944
‘C’ sin(1.256639) 0.951057 ‘VT1419A’ sin(1.256639) 0.950965
‘C’ sin(1.570798) 1.000000 ‘VT1419A’ sin(1.570798) 0.999905
Table 1. ‘C’ Sin(x) Vs. VT1419A Haversine Function for Selected Points
Generating User Defined Functions
Appendix E 379
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