Agilent Technologies E1406A, User'S Manual And Scpi Programming Manual

Page: 58 / 288

Determining the
Table Size
The interrupt line allocation table has a one word header and each data
record contains three words, plus one word for each programmable
interrupter logical address specified. The amount of RAM allocated with
DIAGnostic:NRAM:CREate
is specified in bytes. Since one word is two
bytes, the amount of RAM to allocate is computed as:
2 + 6(N) + 2
å
M
0
N
where
2
is the two byte header,
6
is the number of bytes/data record,
N
is
the number of data records (for example, interrupt lines) and M is the
number of programmable interrupters per data record. For example, to
create a table for the following:
–
one interrupt handler
–
two interrupt lines
–
one interrupter on one line, three interrupters on second line
the table size would be:
2 + 6(2) + 2(4) = 22 bytes
| |
(2 records) (4 interrupters)
DIAGnostic:NRAM:CREate
would be executed as:
OUTPUT @E1406;"DIAG:NRAM:CRE 22"
Note
When assigning an additional interrupt line to an interrupt handler, you
must specify each line. Otherwise, the table will overwrite the line
currently assigned, giving the handler only one line. For example, if the
resource manager assigns interrupt line 2 to a handler and you want to also
assign line 3 to the handler, lines 2 and 3 must be specified in the table. See
“ Example: Assigning an Interrupt Line” on page 57.
Data Format
Data can be sent to the interrupt line allocation table in any convenient
format, as long as the binary data is preserved. This can be accomplished
using
DIAGnostic:PEEK?
and
DIAGnostic:POKE
, by reading the data into a
variable in the computer and then downloading the data to the table using
the Arbitrary Block Program Data format, and so forth. In the following
example, this is accomplished by reading the data into 16 bit integer
variables in the computer and then downloading the data to the table using
the ANSI/IEEE 488.2-1987 Arbitrary Block Program Data format. More
information on the Arbitrary Block Program format can be found on
page 121 of this manual and in the ANSI/IEEE 488.2-1987 document.
56 Configuring the Agilent E1406A Command Module Chapter 2