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C-Link Protocol Commands
Record Layout Definition
The value field displays values which are parsed out of the response to a
DATA/ERec command. It also displays, though background changes,
alarm status. The button, when pressed, triggers input from either a dialog
box or a selection list. There are five kinds of buttons, B, I, L, T, and N.
Each line in the layout string corresponds to one line on the display. The
layout string describes each of the three major fields as well as translation
mechanisms and corresponding commands.
Text
The first field in the layout string is the text. It is delimited by a ':'. The
string up to the first ':' will be read and inserted in the text field of the line.
Value String
This is followed by a possible string enclosed in quotes that is used to place
a string into the value field.
Value Source
The value source, which is the item (or word) number in the DATA/ERec
response, appears next. This is followed by an optional bitfield designator.
The datum identified by the value source can be printed as a string 's',
hexadecimal 'x', decimal 'd', or floating point 'f', or binary 'b' number.
Typically, bitfield extractions are only done for decimal or hexadecimal
numbers.
Floating-point numbers can be followed with an optional precision
specifier which will be used as an argument to printf's %f format (e.g., a
field of '4' would be translated into the printf command of '%.3f').
Alternately, the special character '*' can precede the precision specifier; this
causes an indirection on the precision specifier (which now becomes a field
number).
This is useful when formatting, for example, numbers which have varying
precision depending on the mode of the instrument.
Binary numbers can also have an optional precision specifier which is used
to determine how many bits to print. For example, the specifier 'b4' will
print the lowest four bits of the parsed number.
There are serious restrictions on where an 's' field may appear: currently
sources 1 and 2 must be 's', and no others may be 's'.
Alarm Information
The value source is followed by optional alarm information, indicated by a
commercial at sign '@' with a source indicator and a starting bit indicator.
All alarm information is presumed to be two bits long (low and high). The
bitfield extraction is performed on the integer part of the source. Typical
alarm information would appear as '@6.4'.
Thermo Fisher Scientific
Model 48i Trace Level-Enhanced Instruction Manual
B-43
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Troubleshooting
