This command tells the WLTS to return a verification (self-test) code in response to a subsequent aD0! command. In this case, the WLTS 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 WLTS within 13 seconds to indicate that the BIT operations are complete and the verification code is available.
0D0!/0+000<CR><LF>) is the Send Data command from the SDI-12 recorder 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 | N/A |
| 1 | 2 | WLTS Program Flash Checksum |
| 2 | 4 | WLTS Information Flash Checksum |
| 3 | 8 | WLTS Bootloader Flash Checksum |
| 4 | 16 | N/A |
| 5 | 32 | N/A |
| 6 | 64 | Test Temperature Sensor |
| 7 | 128 | Test Pressure sensor |
Table 5-1 BIT Verification Fault Codes
