B&K 4070A Manual Do Utilizador

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BK Precision 4070A User Manual Rev.2.2 
64 
'****************************************************************************** 
'                               Subroutines 

'  These subroutines take a value in PointVal (which ranges from -1.0 to +1.0) 
'   and converts it to various data formats, (i.e. Floating Point, Binary, 
'   ASCII Hex, and Integer) and then sends that value to the 4070A. 

'  Before the first data point is sent, a Header consisting of two characters  
'   is sent to the 4070A.  The first character of this header is a "W", which 
'   tells the 4070A to expect arbitrary waveform data points. The second 
'   character of the header tells the 4070A what data format to expect, 

'   "F" = Floating Point 
'   "I" = Integer 
'   "H" = ASCII Hexadecimal 
'   "B" = Binary 

' Each subroutine gives a short example of each format. 

'****************************************************************************** 
 
'--------------------- Send Floating Point data to 4070A --------------------- 
' This is the easiest format to use with Basic since no format conversion is  
'  necessary. Basic will output floating point numbers by default. 

' Rules for floating point format: 

' 1. The 4070A expects all floating point values to be between -1.0 and +1.0.  
'    If a number falls outside that range, the number is set to -1.0 or +1.0.  
'    These correspond to the peak values of the waveform.  
'    If the output voltage level were set for 5V p-p, for example, then +1.0  
'    corresponds to +2.5V and -1.0 corresponds to -2.5V (across a 50 ohm load). 
'    For maximum signal fidelity, you should design your waveform so that the  
'    peak values "just fit" into the range of -1.0 to +1.0. You will then be  
'    using the full output range of the DAC. 

' 2. To separate each number, you may use commas, tabs, spaces, carriage  
'    returns and/or linefeeds, semicolons, colons or basically any character  
'    that is not among the following:     
'     0   1   2   3   4   5   6   7   8   9   .   -   +   e   E 

' 3. You do not have to include an exponent (i.e. e-5). If no exponent is  
'    given, the 4070A assumes that the exponent is 0. 

' 4. Whitespace characters are not allowed between the mantissa and exponent. 

' 5. Use of the "+" character for positive values is optional. 

' 6. To set SYNC Out high during a data point, put a "p" or "P"  
'    BEFORE that data point. The "P" character may have whitespace around 
'    it if desired.  SYNC Out is set low for all data points that 
'    do not have a "p" or "P" before them.  

' Examples of floating point numbers, SYNC Out is set high on point #4: 

'   0, .584737, 3457e-4, p  .0004857e+3  -.000485  -1.0e-0 
'------------------------------------------------------------------------------ 
SendFloat: