Met One Instruments 597A, Руководство по эксплуатации

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597A-9800 Manual Rev A Page | 6
Note: when displaying the pressure in In/Hg, there will be an extra leading zero
character but the fixed length of the field will not change.
A check sum parameter will be added to the end of the message (*nnnn). The check
sum is the addition of all the characters from the start of the message through the first
character preceding the asterisk (*). The check sum is expressed as a decimal number.
This is a 16-bit sum and should not overflow past 4 digits, given the number of
characters in the output string.
Polled Data Mode (RS232 or RS485)
The sensor can be set for polled data mode instead of continuous serial output, by
setting the serial trigger string while in terminal mode (see Section 12 for command
details).
SDI-12 Interface
In addition to the above communications methods, the sensor can be polled for data by
an SDI-12 Master Station. This operates completely independent of the RS232 or
RS485 communications and can be used in conjunction with those methods. Data are
polled using a series of SDI-12 commands. Please see appendix E for a list of
supported SDI commands. The default SDI Address for the 597A is zero.
Please consult your data-logger manual for more information on SDI interfaces or call
Met One for additional help.