Agilent Technologies E2730A, Инструкция по установке и эксплуатации

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E2730A VXI RF TUNER
3-6 OPERATION
REGISTER BASED
VXI OPERATIONS
The E2730A supports control of base hardware functions with optimized
binary register based commands. These commands are optimized for
tightly integrated VXI systems. The register based commands save VXI
I/O time and internal tuner firmware processing time. In order to minimize
the processing time required for these commands error checking is
minimal. It is the responsibility of the user application to only send valid
commands and data. The E2730A will accept a combination of binary
register operations and word serial operations with the last operation
executed taking precedence. The available VXI binary commands are
discussed in the following paragraphs.
BINARY COMMANDS
The E2730A may be controlled by writing commands to either the VXI
Device Dependent Registers or through the lower portion of “Upper
Memory” as assigned by the Resource Manager. Binary commands allow
control of frequency and attenuation. The binary commands allow higher
speed operation than the word serial operations. They require less data
transfer time and parsing than the word serial commands. To optimize
performance there is a minimum of error checking with the binary
commands and it is the responsibility of the user’s application to not send
invalid binary commands to the tuner.
The E2730A has the ability to accept VXI commands via the Command
RAM which acts as a bank of registers for Binary Communications. Also,
the same data may be written to the “Upper Memory” area of the VXI
memory. A memory map of the available binary commands is shown in
Table 3-2 . Note that the various parameters associated with the binary
commands have the same value ranges and settings as the word serial
commands, with the exception of the frequency and attenuator commands.
The frequency is entered in units of 10s of hertz. For example, to tune to
214.34560 MHz (0d21434560 = 0x14710c0), the value 0x014710c0 needs
to be written to the frequency data registers (0x0147 to the High Word and
0x10c0 to the Low Word). The attenuator data range is from zero to 30, in
1-dB steps, representing the word serial range of 0 through 60 in 2-dB
steps.