488 CONTROLLER
36
5.2 Command-Description Format
Each command description is divided into several areas.
5.2.1 S
YNTAX
The command description’s syntax section describes the proper command syntax which must be sent to the
488 Controller using the IBM BASIC PRINT# command, or its equivalent in other languages, to the COM
port. The following conventions are used in the syntax descriptions:
No command, along with its options, may be more than 127 characters long. The OUTPUT command’s data
part is not constrained by this length. It is, however, limited to the available USER MEMORY. The OUTPUT
#count;data may be as long as necessary. Refer to the OUTPUT command for more information.
Enter items in capital letters, such as
ENTER
or
OUTPUT
, exactly as stated, except use abbreviations with
some commands to reduce serial transmission traffic.
Items in lower case, such as
addr
or
count
, represent parameters which must be substituted with an
appropriate value.
Blank spaces in commands are generally ignored. Thus,
LOCAL LOCK OUT
is the same as
LOCALLOCKOUT
. Spaces are not ignored in four places: the
OUTPUT
command’s data part, within
quoted strings in a
SEND
command, after an apostrophe (') in a terminator specification (
term
), and after
the semicolon following the
ID
command.
The number sign (
#
) and the semicolon (
;
) must be present exactly as shown. A comma (,) represents an
address separator. You can use the slash (
/
) or period (
.
) in its place as the address separator.
Use optional semicolons ([;]) if desired.
Items enclosed in square brackets (
[item]
) are optional. Multiple items enclosed in square brackets
separated by vertical lines (
[item1|item2|item3]
) are optional; any one or none may be chosen. No more
than one item may be selected.
Ellipses (
...
) within square brackets mean that the items in the brackets may be repeated as many times as
desired.
Braces, or curly brackets (
{item1|item2}
), mean that exactly one of the enclosed items is required.
Bracket combinations are possible. For example,
{term[term] [EOI] |EOI}
allows the choice of “term,” “term
EOI,” “term term,” “term term EOI,” or just “EOI,” but does not allow the choice of “nothing.”
Numeric parameters (those that are given as numbers) are decimal unless preceded by &H, in which case
they are considered to be hexadecimal. Thus 100 is decimal 100, &H64 is hexadecimal 64 which equals
decimal 100, &HFF is decimal 255, and 0FF is invalid because F is not a valid decimal digit. The only
exception to this rule is that bus addresses, both primary and secondary, must be specified as two-digit
decimal numbers. Hexadecimal bus addresses are not allowed.
Several commands require additional or optional parameters. These are further described with each
command, but the more common ones are discussed next.
Содержание 488 Controller
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Страница 95: ...93 CHAPTER 9 Theory of Operation Board Layout Figure 9 2 The interface converter s serial I O board...
Страница 102: ...488 CONTROLLER 100 How To Read the Chart Hexadecimal Decimal Equivalent Equivalent ASCII Character Address or Command...
