Rohde & Schwarz R&S RTB2004 - Page 252

Remote Control Commands
R&S
®
RTB2000
244User Manual 1333.1611.02 ─ 04
FORM UINT,8;FORM? // Set data format to unsigned integer, 8 bit
<-- UINT,8
CHAN:DATA:YINC? // Read voltage value per bit
<-- 1.999999949E-4
CHAN:DATA? // Read channel data
<-- 128,125,120... // 5000 bytes total
FORM UINT,16;FORM? // Change data format to unsigned integer, 16 bit
<-- UINT,16
CHAN:DATA:YINC? // Read voltage value per bit
<-- 7.812499803E-7
CHAN:DATA? // Read channel data
<-- 32768,32000,30720... // 10000 bytes total
Note the following correlations:
●
The number of received data values matches the number of samples indicated in
the header.
●
The time of the first sample (XORigin) matches the start time Xstart indicated in the
header.
●
The Y-increment adjusts to the data length defined in the data format (8 or 16 bit).
Data conversion
Definition: the sample numbers start with 0 and end with record length - 1.
Sample time
t
n
= n * xIncrement + xOrigin
First sample: t
0
= -4.998000058E-7 (= Xstart)
Last sample: t
4999
= 4999 * 2E
−10
− 4.998E
−7
= 5.0 E
−7
(= Xstop)
Sample value
Y
n
= yOrigin + (yIncrement * byteValue
n
)
The format UINT,8 has the data range 0 to 255. The voltage value for byte value 128
is:
Y
n
= −2.55E
-2
+ (2E
−4
* 128) = 0.0001
The center of the display at position 0 div always has the byte value 127.5. The corre-
sponding voltage value is:
Y
n
= −2.55E
-2
+ (2E
−4
* 127.5) = 0
8-bit and 16-bit data
At the end of the above example, the 8-bit waveform is read as 16-bit data, for exam-
ple, 0xFF is read 0xFF00, or 0x1A is read 0x1A00. The yOrigin value is the same in
both cases, but the yIncrement differs.
Programming Examples