Setup guide

Chapter 3 Driver and Protocol Objects
Object Reference Manual 3-30 www.Automationdirect.com
character. The corresponding input field is read up to the first character that
does not appear in the bracketed character set. Using a caret (
^) as the first
character in the set reverses this effect: the ASCII object reads input field
up to the first character that does appear in the rest of the character set.
Notice that %[a – z] and %[z – a] are interpreted as equivalent to
%[abcde…z], and that the character set is case sensitive. Valid control
characters accepted include \a, \A, \b, \B, \f, \F, \n, \N, \r, \R, \t, \T, \v, \V, \\,
\’, \”, and \?.
Any ASCII character can be specified in the format string using \xbb or
\nnn masks. \xbb is a hexadecimal byte with each b representing a valid hex
character in the range (0...9, a...F), for example \xff or \x1a.
\nnn is an octal byte with each n being a valid octal character in the range
0 to 7, for example \123 or \347. THis value may not exceed 255 as it is
meant to represent a single byte of data. These two features can be used to
create and compare static characters. These can also be specified in the
regular expression, for example %[\xff, \123, \a, \b] is a valid frame.
Note
The brackets only work in response format strings. They have no effect in the
request format string.
The ASCII object scans each field in the response frame character by
character. It may stop reading a particular field before it reaches a character
for a variety of reasons:
• The specified width has been reached.
• The next character cannot be converted as specified.
• The next character conflicts with a character in the response format
string that it is supposed to match.
• The next character fails to appear in a given character set.
No matter what the reason, when the ASCII object stops reading a field,
the next field is considered to begin at the first unread character. The
conflicting character, if there is one, is considered unread and is the first
character of the next field.
Response
Format String
RSV1.txt
Response
Frame
$%[A – Z,a – z, ]$ Natl Inst $Natl Inst$
>%[^,s] days >day