Solinst AquaVent SDI-12, Руководство пользователя

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SDI-12 User Guide for AquaVent
Page 15
5.9 Start Concurrent Measurement Command with Checksum: aCC!
This command is similar to the Start Concurrent Measurement with the addition
of a checksum. For example: 0CC! 000302<CR><LF> would then, after 3
seconds, reply to the aD0! command as follows:
0D0! 0+24.6038+0.34513L<DEL>j<CR><LF>. Where “L<DEL>j” is the
checksum for the two measurement values “+24.6038 + 0.34513. The aCC1
to aCC9 commands are reserved for future use.
5.10 Start Verification Command: aV!
This command tells the SPX Wellhead to return a verification (self-test) code in
response to a subsequent aD0! command. In this case, the SPX Wellhead returns
a non-zero time because the self-test execution verifies all internal memory
checksums and these operations take about 13 seconds. A typical session would
appear as follows:
0V! 00131 <CR><LF> indicates that one status reading will be ready in about
13 seconds.
0<CR><LF> is a service request from the SPX Wellhead within 13 seconds
to indicate that the BIT operations are complete and the verification code is
available.
0D0!0+000 is the Send Data command from the SDI-12 master device to obtain
the BIT verification code of “+000” which indicates that no faults were found.
The possible fault codes are shown in Table 5-1. All the decimal representations
of the individual faults are summed to arrive at the resultant BIT verification
code. An included bit in a certain bit position means the corresponding test has
failed.
Code Bit Position Decimal Representation Test Meaning
0 1 Read Write AquaVent logger
1 2
SPX Wellhead
FRAM Memory Test
2 4
SPX Wellhead FLASH
Memory Checksum Test
3 8 N/A
4 16 N/A
5 32 N/A
6 64 N/A
7 128 N/A
Table 5-1 BIT Verification Fault Codes