Fluke PM-3384B, PM-3380B Using the Combiscope Instruments Program Example, ’1-byte samples

USING THE COMBISCOPE INSTRUMENTS 3 - 35

PROGRAM EXAMPLE:

In this program example a trace of 512 samples from the actual signal at input channel 1 is read. The received data block is converted to an array of voltages. After each sample conversion the voltage value is printed. This program example works for traces of 512 samples, consisting of 8 bits (1 byte) or 16 bits (2 bytes) samples.

Note: The program is supplied on floppy under file name EXCNVTRC.BAS.

DIM sample(512)		’Array of sample voltages
DIM response AS	STRING * 1033	’Trace data response string
DIM peaktop AS STRING * 10		’Peak-to-peak response string
DIM offs AS STRING * 10		’Offset response string
’		’Resets the instrument
CALL Send(0, 8,	"*RST", 1)
CALL Send(0, 8,	"CONFigure:AC (@1)", 1)	’Configures for optimal AC-RMS settings
		’Signal-offset also becomes zero
CALL Send(0, 8,	"INITiate", 1)	’Initiates single acquisition
CALL Send(0, 8,	"*WAI;TRACe? CH1", 1)	’Requests channel 1 trace
CALL Receive(0,	8, response$, 256)	’Reads channel 1 trace

’

nr.of.digits = VAL(MID$(response$, 2, 1))

nr.of.bytes = VAL(MID$(response$, 3, nr.of.digits)) - 2

sample.length =	ASC(MID$(response$, 3 + nr.of.digits, 1))
nr.of.samples =	nr.of.bytes / (sample.length / 8)	’Queries ptp
CALL Send(0, 8,	"SENSe:VOLTage:RANGe:PTPeak?", 1)
CALL Receive(0,	8, peaktop$, 256)	’Reads ptp
ptpeak = VAL(LEFT$(peaktop$, IBCNT%))		’IBCNT% = length
CALL Send(0, 8,	"SENSe:VOLTage:RANGe:OFFSet?", 1)	’Queries offset
CALL Receive(0,	8, offs$, 256)	’Reads offset
offset = VAL(LEFT$(offs$, IBCNT%))		’IBCNT% = length
IF sample.length = 1 THEN		’1-byte samples
FOR i = 1 TO nr.of.samples
trace% = ASC(MID$(response$, i + 3 + nr.of.digits, 1))
IF trace% >	127 THEN trace% = trace% - 256
END IF
sample(i) =	trace% / 200 * ptpeak - offset
PRINT sample(i);
NEXT i
ELSE		’2-byte samples
FOR i = 1 TO nr.of.samples
J = 2 * i +	2 + nr.of.digits	’Pointer to next sample
byte1 = ASC(MID$(response$, J, 1))		’M.S.B.
byte2 = ASC(MID$(response$, J + 1, 1))		’L.S.B.
IF byte1 < 128 THEN trace% = byte1 * 256 + byte2
ELSE trace%	= (byte1 - 256) * 256 + byte2
END IF
sample(i) =	trace% / 51200 * ptpeak - offset

PRINT sample(i);

NEXT i

END IF