Keithley 6514, Инструкция по эксплуатации

Страница: 117 / 334

8-6 Buffer
G) CALCulate3:FORMat <name>
This command selects the statistic to be returned by CALCulate3:DATA? (see Ref H). Name
parameters:
• MINimum — Select the lowest reading stored in the buffer.
• MAXimum — Select the largest reading stored in the buffer.
• MEAN — Select the mean average statistic for the readings stored in the buffer.
• SDEViation — Select the standard deviation statistic for the readings stored in the buffer.
• PKPK — Select the peak-to-peak statistic for readings stored in the buffer. Peak-to-Peak
is calculated as follows: PKPK = MAXimum - MINimum.
H) CALCulate3:DATA?
1. If the number of data points in the buffer is one or none, CALCulate3:DATA? will result
in an error (-230).
2. If there is a lot of data in the buffer, some statistic operations may take too long and cause
a bus time-out error. To avoid this, send calc3:data? and then wait for the MAV (message
available) bit in the Status Byte Register to set before addressing the Model 6514 talk
(see Section 13).
Programming example
The following program fragment stores 20 readings into the buffer and then calculates the
mean average on the buffer readings:
‘ Select data elements:
*RST
‘ Return 6514 to RST defaults.
FORM:ELEM READ,TIME ‘ Select reading and timestamp.
‘ Store and Recall Readings:
TRAC:POIN 20
‘ Set buffer size to 20.
TRAC:FEED SENS ‘ Store raw input readings.
TRAC:FEED:CONT NEXT ‘ Start storing readings.
TRAC:DATA? ‘ Request all stored readings.
‘ Acquire Mean Statistic for Buffer Readings:
CALC3:FORM MEAN
‘ Select mean statistic.
CALC3:DATA? ‘ Request mean statistic.