Manual – Starflow QSD Model 6527B and 6537A
Unidata Manual - 6527B and 6537A Starflow QSD User Manual 08 05 2023.docx
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5. TAKING MEASUREMENTS FROM INSTRUMENT
The Starflow QSD instrument has both SDI-12 and RS485 (Modbus RTU) Interfaces. The
following sections describe them in detail. If you are a user of Unidata NRL loggers, you can
simply add the Starflow QSD as an instrument within the logging scheme as an SDI-12
instrument.
5.1. SDI-12 Operation
The Starflow QSD can be operated as a standard SDI-12 (V1.3) sensor.
Measurement commands (M! & C!) return atttn(n) response with ttt indicating the delay until
measurements are ready and n(n) indicates the number of parameters returned.
A Service Request is sent.
- The R! command returns an acknowledge response a<CR><LF>
- The D! command returns the measured data values.
SDI-12 Command Notes:
1.
Change Address aAb! is supported.
2.
Start Verification aV! returns an acknowledge response.
3.
Extended Command aX is supported (refer to QSD SDI-12 supplement document).
4.
D/R1…9! Commands operate the same as a D/R0! command.
5.
M/C1...9! Commands operate the same as an M/C! command.
6.
MC, CC & RC commands requesting CRC are supported.
Note: CRC is always recommended