Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 141)

8P. Command Descriptions II. SOFTWARE GUIDES - 8. Driver488/DRV
II-126 Personal488 User’s Manual, Rev. 3.0
formats available for Driver488/DRV. For more detail on the individual system commands, see
“Section III: Command References.”
Format
The format for the Driver488/DRV command descriptions consists of several sections which together
define the command. Using the QuickBASIC language, this format is implemented for the system
commands found in Sub-Chapter 15A: “Driver488/DRV Commands” of the “Section III: Command
References” in this manual.
Syntax
The Syntax section of the system command description describes the proper command syntax that must
be sent to Driver488/DRV. The following conventions for syntax descriptions, use the QuickBASIC
language:
•
No command may be more than 255 characters long. The data part of the OUTPUT command does
not count in this length and so the OUTPUT data may be as long as necessary.
•
Items in upper case, such as ENTER or OUTPUT must be used exactly as stated except that command
keywords are not case sensitive: Enter , enter , ENTER , and eNtEr are all equivalent.
•
Items in lower case, such as addr or count , represent parameters that must be substituted with an
appropriate value.
•
Blank spaces in commands are generally ignored. Thus, LOCAL LOCKOUT is the same as
LOCALLOCKOUT . Spaces are not ignored when: in the data part of an OUTPUT command, within
quoted strings in a SEND command, after an apostrophe ( ‘ ) in a terminator specification ( term ), at
the end of a device name, or within a number.
•
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. For example [,addr...] means that any number of address separator-
address combinations may be used.
•
Braces, or curly brackets, ( {item1|item2} ) mean that exactly one of the enclosed items is
required.
•
Combinations of brackets are possible. For example, {term[term][EOI]|EOI} allows the
choice of term , term term , term term EOI , 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 or 0X , in
which case they are hexadecimal. Thus, 100 is decimal 100 , &H64 is hexadecimal 64 which
equals decimal 100 , 0XFF 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 decimal numbers. Hexadecimal bus addresses are not allowed.
Several of the commands are accompanied by required or optional syntax parameters. These are
further described with each command, but the more common ones are discussed below, using
QuickBASIC:
Bus Addressing
•
pri-addr : A primary device address in the range 0 to 30 .
•
sec-addr : An optional two-digit secondary device address in the range 00 to 31 .
•
name : A one- to eight-character device name composed of letters, numbers, and underscores
( _ ) used to represent the address of a particular bus device.