Agilent Technologies E1445A, User'S Manual And Scpi Programming Manual

Page: 486 / 534

System
Configuration
The example programs and programming techniques shown in this appendix
are based on the following system configuration:
Mainframe: Agilent 75000 Series C (Agilent E1401)
Controller: Agilent E1480A V/360 (select code 16)
Programming Language: BASIC/UX (6.0)
Agilent E1445A AFG: Logical address = 80
Each program uses a combination of SCPI commands and register
reads/writes. In most cases, SCPI commands set up the AFG and initiate
the waveform. Register reads/writes are used to change the frequency,
phase, waveform, etc., instantaneously.
Accessing the Registers
Access to the AFG’s operational registers is through addresses mapped into
A24 address space. At power-on, the system resource manager reads the
AFG’s Device Type Register (in A16 address space) to determine the
amount of A24 memory the AFG requires. Once known, the resource
manager allocates a block of A24 memory to the AFG and writes the base
(starting) address into the AFG’s Offset Register.
Determining the
A24 Base Address
When you are reading or writing to an AFG register, a hexadecimal or
decimal register address is specified. The register address is the sum of:
A24 base a register number
The base address of the AFG operational registers in A24 address space is
determined by reading the AFG’s Offset Register and multiplying the value
by 256 (100
16
). This converts the 16-bit value of the Offset Register to a
24-bit address.
The register number is identified in the register descriptions found in the
following sections.
484 Register-Based Programming Appendix C