Tektronix 2230

Options—2230 Service
Table 7-21 (cont)
Waveform Preamble Fields (cont)
Header
Argument
Link
Argument Description
WFMpre (cont)
PT.Off
<NR1 >
Point offset identifies the trigger position relative to the first
point of the waveform. For a 1024 point record PT.Off normally
varies between 4 and 1024 in increments of 4. Normal range
with 4096 point records is between 4 and 4096. NOTE: PT.Off
returns a negative value if the trigger occurred before the first
point of the waveform. Since a 1024 record portion of a 4096
point record can be transferred, legal values for PT.Off range
from —3076 to +4096. If the value is unknown, —10000 is
returned.
PT.Fmt
Point format defines how to interpret the curve data.
Y
Y format means that X information is implicit and that data
points are Y values.
XY
XY format means that data points are XY pairs, with X first.
ENV
Format used for envelope waveforms. The data is sent in the
form: ..., ylmax, ylmin, y2max, y2min,... ENV is valid' for
PEAkdet and ACCpeak when SMOoth is OFF.
XUNits S
CLKs
If the argument is S, the XINcr value is in seconds. If it is CLKs,
the scaling is unknown (EXTCLK).
XINcr <NR3>
Value gives the time interval between points (sampling rate). If
<NR3> does not correspond to a legitimate time/div setting,
the nearest legitimate setting is substituted and a warning SRQ
is issued if EXW is ON. For a query response with an unknown
time/div (i.e. EXTCLK), <NR3> is set to 1.
YUNits
V
DIV
Indicates the units associated with YMUIt.
YMUIt
<NR3>
This value gives the vertical 'step’ size of the digitizer (volts
between points). If <NR3> does not correspond to a
legitimate volts/div setting it is treated as a “variable” setting
and a warning SRQ is sent. On a query response, an unknown
vertical scaling (i.e. variable) sets <NR3> to 0.04 (25 pts/div).
YOFf <NR1>
YOFf is the Y coordinate of ground. If ground is unknown,
— 10000 is returned.
7-24