INFICON STC-2002 Thin Film Deposition Controller Operating Manual - Manual (Page 244)

p STC-2002 DEPOSITION CONTROLLER y
SECTION 6.XX e page 242 of 276 ^
These commands Read and Set I/O rung expression contents. Follow M with number n for which
rung is to be read (n can be 1,2 or 3 digits from 1 to 999). If the M command is followed immediately by =
, it means repeat the transmission of the same information. If it is followed immediately by + , it means
advance to the next portion of rung information. This is needed in order to keep the I/O buffers short. It is
possible for the rung length to exceed the STC-2002 buffer which is 13 bytes long. In this case it is broken
up into several lines of information.
If
n is beyond the last rung with contents, the STC-2002 will return end and the rung number of
the END rung as follows: "A.END nn".
The
N command is used to change a rung to new data. The N is followed with number n to
identify which rung to change. After the initial N command, subsequent 'O' commands specify the new
rung data.
The
O command sends an I/O expression to the STC-2002. The O is followed immediately with
either a period ('.') or a sequence digit '0' .. '9' and the ASCII rung information. The entire string of the 'O',
the '.' or digit, and the following rung symbolic must not exceed 13 characters. Lines longer than this use
the sequence number to indicate a continuation is needed, with the final portion (or only portion if small
enough) having a '.' where the digit goes.
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Command: M
Mnemonic: EXCT_iord
(I/O read)
Parameters: [1..LASTRUNG] or [=] or [+]
Description: Requests a read-back of the current active I/O program's symbolic I/O rung data
expression. If 1..LASTRUNG (where LASTRUNG is any number greater than or equal to the actual
last rung in program storage) then the command will return the reply result (RZCD_AOK, etc..) followed
by a sequence code (see description below) followed by symbolic rung expression data. A simple example
exchange will clarify this:
SEND: Description
RECEIVE: Description
M 1 Request Rung 1
A0I18 P109 + Part of rung sequence code 0
indicates 1
st part of line.
M= Request to resend last data without
scanning ahead to remainder of line.
A0I18 P109 + Used if a com link error
caused last data to be lost. This way
there is no need to start at beginning
of rung again.
M+ Request additional information as the
previous reply had a sequence code #
(0..9) rather than a '.' as terminator.
A.S8 Final contents of rung sent in
response to the M+ advance
command. Un-limited numbers of
M= can be sent to request this again
until received without data error.
Returns:
[RZCD_AOK][SEQUENCE_CODE][RUNG_SYMBOLIC_DATA] if proper parameters were
sent. Exact content of [SEQUENCE_CODE] and [RUNG_SYMBOLIC_DATA] depend
on what was programmed into the I/O program. If the rung # parameter is beyond the last
rung of the I/O program, then the STC-2002 will return "A.END nn" with nn being one
rung beyond the last valid rung number. In this way the length of the program can be
ascertained by reading back with a M999 request. This is sure to be longer than the
current program (storage allows for a maximum of about 400 rungs) and will respond
with the rung number of the last line of the I/O program.