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Metrohm 774 Oven Sample Processor User Manual

Page 86

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5 Detailed description

774 Oven Sample Processor, Instructions for use

80

Setting special bit patterns allows flexible control of connected instruments.

Here the following is valid:

0 = line inactive

1 = line active

* = arbitrary line state


Example:

00000001 = input 0 is active = instrument 1 "Ready"


The bit pattern (= line state ) can be taken over interactively with the LEARN
function. See page 34.

Details about the remote interface are found on page 97.

1

SCAN

>sample sequence

8 SCN:RS

Rm,RS

Clear value: ∗R"

14 ASCII characters

Scanning the RS232 interface

= scan for "Ready" status message

arbitrary series of 14 characters

In a sequence the SCN:RS command causes method processing to stop
until the predefined character string (up to 14 characters) is received via se-
rial RS 232 interface. The received data is compared character by charac-
ter.

Be sure that the interface parameters agree with those of the instrument
connected (see Configuration Menu '>RS232 settings', page 66).

Any letters, numbers and special characters from the character set of the
sample changer can be chosen.
The asterisk (*) may be used as a wildcard for an arbitrary character or
character string. (If '*' is to be interpreted as an ASCII character, '**' has to
be set.) A wildcard may be used in any position of a character string. If the
first part of character string is correctly identified, the first appearance of the
character following the asterisk (*) is scanned. When it is found, the next
part of the character string is compared.
This function is especially suited to instruments with Metrohm remote con-
trol language. Here the Auto-Info status messages can be scanned. The
most useful of these are:

*.T.R"

Ready, 'ready' state attained, for ex., after titration

*.T.F"

Final, end of the determination is reached

*.T.S"

Stop, instrument manually halted

*.T.G"

Go, instrument was started

*.E;*

Error, error message


'*' can be set as a wildcard for a particular character string. Example: *R"
instead of !".T.R" (status message 'ready' after completing a titration).

These status messages however, are only transmitted if the corresponding
status message has been previously switched on, for example, in the the
start sequence with the command:

CTL:RS &Se.A.T.R"ON", for example.
CTL command, see below.

With the LEARN function transmitted data (=character strings) can be
taken over interactively. See page 34.