B&K 4070A user manual Subroutines

'******************************************************************************

'	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:

64

BK Precision 4070A User Manual Rev.2.2