Xylem H-3342 - Manual (Page 26)

3-14 SDI-12 Command and Response Protocol
H-3342
3.14 Extended Read SDI_Digits and Write SDI_Digits
This command is used to change the number of SDI-12 digits beyond the decimal point. The
LCD display can display the Stage in one of two formats: ±199.99 or ±19999. By default SDI-12
measurement data is sent with more precision than will fit on the LCD display. The default is
three digits (x.xxx). Some users prefer to have the SDI-12 measurement data exactly match the
value on the LCD display. If this is the case, use this command and set SDI-Digits to 2, such that
two digits beyond the decimal point are sent in the SDI-12 response (x.xx).
Once a new value is written, a copy is sent to the sensor data buffer for verification. This data
can be viewed by using a subsequent "D" command. To read or verify the value any other time,
use the "XRSDI" command.
Command Response Description
"aXRSDI!" “a0011" Read SDI_Digits
"aXWSDIn!" “a0011" Write SDI_Digits
Where: a is the sensor address ("0-9", "A-Z", "a-z", "*", "?").
XRSDI are upper case characters.
XWSDI are upper case characters.
n is the new setting (0 - 4)
This command takes 001 seconds to complete and places 1 value in the data buffer. Use the
“aD0" command to collect and view the current value.
Example of a H-3342 Extended "Read SDI_Digits" command:
Command Response Time Values Description
"aXRSDI!" "a0011" 1 sec 1 Read SDI_Digits
Command Response Description
"aD0!" "a+3" Format is ±xx.xxx
Example of a H-3342 Extended "Write SDI_Digits" command:
Command Response Time Values Description
"aXWSDI2!" "a0011" 1 sec 1 Write SDI_Digits
Command Response Description
"aD0!" "a+2" Format is ±xx.xx