Giga-tronics 8650A Series, Operation Manual

Page: 30 / 240

Series 8650A Universal Power Meters
1-10 Manual 31470, Rev. E, April 2001
Measurement Rates
Table 1-1 illustrates typical maximum measurement rates for different measurement collection modes.
The rate of measurement depends on several factors including the controller speed and the number of
averages. The Fast Buffered Mode speed does not include bus communication time. Measurement speed
increases significantly using the 8650A Fast Buffered Mode. Storing data in the power meter’s memory
for later downloading to your controller reduces GPIB protocol overhead. Up to 5000 readings can be
buffered.
Individual data points are read immediately after measurement in the Normal mode. The Normal mode
and the Swift mode both slow down at low power levels (<-37 dBm for Standard Sensors) to average the
effects of noise. The Swift mode allows triggering of individual data points and can store the data in the
8650A memory. Measurement timing of individual data points is controlled by setting the time interval
(0 to 5000 ms) between the data points following a trigger.
Remote Operation
GPIB Interface: All front panel operations and some GPIB-only operations to be
remotely programmed in IEEE 488.2 or IEC-625 formats.
Interrupts:
SRQs are generated for the following conditions:
Power Up, Front Panel key actuation, Operation Complete and
Illegal Command.
Fast Buffered Mode Controls
Trigger Source: TTL or GPIB
Data Buffer Control: Pre- or Post-measurement data is collected immediately either
before or after receipt of the TTL or GPIB trigger.
Time Interval:
TIME ### - controls time interval in milliseconds between
measurements. Accurate to 5%, typical.
Table 1-1: Measurement Rates
Measurement
Collection Mode
Readings per Second
(CW Measurement)
Readings per Second
(MAP, PAP, BAP
Measurement)
Normal (TR3), Continuous Single
Readings >300 150
Swift Mode, Continuous or
Buffered, Bus/TTL triggered
>1750 800
Fast Buffered Mode, Buffered Data, Time
Interval = 0 26,000 N/A
Fast Modulated Mode, Continuous Single
Readings N/A 800