User`s manual

Chapter 6 117
Advanced Operations
Increasing Measurement Throughput
Optimizing the Execution Speed of the Control
Program
Execution speed of the control program is defined as the time required
to execute a given number of program lines.
Each time the HP-IB is accessed, a given amount of time is required to
configure the devices on the bus for data transfer. Every time a BASIC
or IBASIC OUTPUT or ENTER statement is executed this bus
configuration time is incurred. The total amount of bus configuration
time expended for a given number of program lines can be minimized by
reducing the number of OUTPUT and ENTER statements used in the
control program. This is accomplished by combining several commands
into one HP-IB transaction. Execution speed of the control program is
influenced by the use of compound commands and screen display time
as described in the following paragraphs.
Compound Commands for Combining OUTPUT Statements
To reduce the number of OUTPUT statements used to make the desired
settings within one screen, string together multiple settings within one
OUTPUT statement. This is accomplished using the ; (semicolon)
separator and the ;: (semicolon colon) separator.
The ; (semicolon) Separator The ; (semicolon) separator tells the
Test Set’s HP-IB command parser to back up one level of command
hierarchy and accept the next command at the same level as the
previous command. The following examples illustrate proper use of the
semicolon separator:
Example 6-5 Example #1
OUTPUT 714;"RFG:AMPL -66 DBM;FREQ 500 MHZ;AMPL:STAT ON"
This OUTPUT statement sets the RF generator’s amplitude, frequency,
and output state.
Example 6-6 Example #2
OUTPUT 714;"RFG:MOD:EXT:DEST ’FM (/Vpk)’:FM 12.5 KHZ;FM:STAT ON"
This OUTPUT statement configures the RF generator to accept
external modulation from the rear-panel input, sets the amount of
deviation, and turns FM on.