Teledyne API T703/T703U Calibrator Operation Manual Communications
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decimal point.) Scientific notation is not permitted. For example, +1.0, 1234.5678, -
0.1, 1 are all valid floating-point numbers.
Boolean expressions are used to specify the value of variables or I/O signals that
may assume only two values. They are denoted by the keywords ON and OFF.
Text strings are used to represent data that cannot be easily represented by other
data types, such as data channel names, which may contain letters and numbers.
They consist of a quotation mark, followed by one or more printable characters,
including spaces, letters, numbers, and symbols, and a final quotation mark. For
example, “a”, “1”, “123abc”, and “()[]<>” are all valid text strings. It is not possible to
include a quotation mark character within a text string.
Some commands allow you to access variables, messages, and other items. When
using these commands, you must type the entire name of the item; you cannot
abbreviate any names.

5.1.7.4. Status Reporting

Reporting of status messages as an audit trail is one of the three principal uses for the
RS-232 interface (the other two being the command line interface for controlling the
instrument and the download of data in electronic format). You can effectively disable
the reporting feature by setting the interface to quiet mode (Section 5.1.4, Table 5-1).
Status reports include warning messages, calibration and diagnostic status messages.
Refer to Appendix A for a list of the possible messages, and this for information on
controlling the instrument through the RS-232 interface.

5.1.7.5. General Message Format

All messages from the instrument (including those in response to a command line
request) are in the format:
X DDD:HH:MM [Id] MESSAGE<CRLF>
Where:
X is a command type designator, a single character indicating the message
type, as shown in the Table 6-27.
DDD:HH:MM is the time stamp, the date and time when the message was issued. It
consists of the Day-of-year (DDD) as a number from 1 to 366, the hour of
the day (HH) as a number from 00 to 23, and the minute (MM) as a
number from 00 to 59.
[ID] is the calibrator ID, a number with 1 to 4 digits.
MESSAGE is the message content that may contain warning messages, Test
Functions, variable values, etc.
<CRLF> is a carriage return / line feed pair, which terminates the message.
The uniform nature of the output messages makes it easy for a host computer to parse
them into an easy structure. Keep in mind that the front panel display does not give any
information on the time a message was issued, hence it is useful to log such messages
for trouble-shooting and reference purposes. Terminal emulation programs such as
HyperTerminal can capture these messages to text files for later review.
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