Manual – Starflow QSD Model 6527B and 6537A
Unidata Manual - 6527B and 6537A Starflow QSD User Manual 17 01 2020.docx
Page 8
4.0 TAKING MEASUREMENTS FROM THE 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 a SDI-12 instrument
4.1 SDI-12 Operation
The Starflow QSD can be operated as a standard SDI-12 (V1.3) sensor.
Measurement commands (M! & C!) returns atttn(n) response with ttt indicating the delay until
measurements are ready and n(n) indicates the number of parameters return.
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 (see below for details)
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
4.1.1 Measure Parameters
Measured parameters – 6527B/6537A Starflow QSD measures several parameters and these are
available for collection by a data logger. Up to 16 parameters are supported and the default
configuration only returns 9 parameters. The parameters are associated with the instrument internal
Channels. The parameters can be configured to return in any sequence (see extended commands
below). The default sequence parameters are listed below:
Parameter Description
Units
Example Meaning
1
Water Temperature
1/10 ºC
+152
15.2ºC
2
Battery Voltage
1/100 Volts
+1302
13.02Volts
3
Ultrasonic Depth
mm
+123
123mm
4
CW Water Velocity
+/- mm/s
-234
234mm/s -ve flow
5
RSSI (signal level)
no units
+66
66 (no units)
6
Signal Spread
no units
+45
45 (no units)
7
Conductivity (TC)
µS/cm
+2350
2350µS/cm
8
Pressure Depth
+/- mm
+123
123mm
9
Barometric Reference
+ mm
+10120
10120mm
