Computer Configurations
This sec tion contains perf or mance and functi ona l informati on on the
computer configurations that can be used with register-based
programming.
Throughput Speed Throughput speed is based on the amount of c ommand parsing and
whether the registers are accessed from t h e VXI backplane or from the
GPIB. The computer conf igurations which allow faster throughput
relative to each other are summarized below:
1. Agilent E1480A V/360 Contro ller with REA DIO an d WRITE IO
(registe r access is from V XI backp lane).
2. E1405/06 IBASIC ab solute addr essing with READ IO and
WRIT EIO ( register access is from VX I backplan e).
3. E1405/06 IBASIC se lect code 8 with R EADIO and WR ITEIO
(registe r access is from V XI backp lane).
4. Exter nal Com pute r using D IAG:P EEK? and DI AG:PO KE
(register access is over GPIB).
5. External Computer using VXI:READ? and VXI:WRITE
(register access is over GPIB).

Embedded

Computer

Programming

(C-Size Systems)

The fastest throug hput is achieved using an embedded computer such as
the Agilent E1480 V/360. The e mbedded co mputer allows you to access
the amplifier reg isters from the VXIbus backpl ane, and since READIO
and WRITEIO are used, there is no parsing of SCPI command headers.

IBASIC

Programming When th e E1446A amp lifier is programmed u sing the E1405/06
Command Module’s Instrument BASIC (IBASIC), two methods of
accessing t he re gisters a re thr ough ab solute addre ssing or usin g select
code 8.
Absolute Addressing and Select Code 8
Absolut e addr essing is fast er th an select code 8 sin ce the comple te
register address (including the A16 starting location 1FC00016) is
specified. When select c o de 8 is used, the IBASIC proces sor must
calculate the comp lete register address based on the logical address
specifie d (Table C-1).

C-4 Register-Based Progr amming Computer Co nfigurations