5.10 Start Verification Command (aV!)

This command tells the Levelogger to return a verification (self-test) code in response to a subsequent aD0! command. In this case, the Solinst Levelogger returns a non-zero time because the self-test execution verifies all internal memory checksums and these operations take about 3 seconds. A typical session would appear as follows:


0V!00031<CR><LF> indicates that one status reading will be ready within 3 seconds.


0<CR><LF> is a service request from the Levelogger within 3 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 2. 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 Solinst Levelogger
1 2 Solinst SDI-12 Interface Cable
FRAM Memory Test
2 4 Solinst SDI-12 Interface Cable
Memory Checksum Test
3 8 Solinst SDI-12 Interface Cable
Voltage Test
4 16 N/A
5 32 N/A
6 64 N/A
7 128 N/A

Table 5-1 BIT Verification Fault Codes