Section 6: Reading buffers
2470 High Voltage SourceMeter Instrument Reference Manual
6-4
2470-901-01 Rev. A /
May
2019
The System Events tab on the
(on page 3-37) displays the following buffer
events:
•
Event code 4915, "Attempting to store past capacity of reading buffer," which occurs when a
buffer that is set to fill once is full.
•
Event code 4917, "The fill status of
bufferVar
is 0% filled."
•
Event code 4918, "Reading buffer
bufferVar
is 100% filled."
Figure 104: System Events tab
Timestamps
The measurements in the reading buffers contain timestamps. Readings start at the first entry in the
empty reading buffer. Readings are then taken sequentially until the end of the buffer is reached. If
the buffer fill mode is continuous, readings wrap to the first entry and fill again. The relative time is
taken from the first reading made after a buffer is cleared.
For a buffer that fills once, the first entry starts at index 1 with the timestamp in absolute time. For
continuous buffers, the lowest timestamp is after the last entry. For example, if you take 150 readings
into a buffer with a capacity of 100, the last reading is at entry 50 and the earliest reading is at 51.
The buffer style you select when creating a buffer affects the resolution of the timestamp. For the
Compact buffer style, the timestamp is a 1 µs accuracy relative timestamp with a one-hour time span
before the timestamp starts over. For Standard and Full buffer styles, the timestamp is absolute; full
date and time is recorded.
