Xylem H-3342 - Manual (Page 23)

H-3342
SDI-12 Command and Response Protocol 3-11
3.11 Extended Read/Write Stage_Offset and Read/Write Stage_Slope
The H-3342 processes the raw shaft position with a Stage = mX+b equation. The Slope (m) and
Offset (b) terms are programmable, allowing the user to scale the reading into other engineering
units. These commands allow the user to read or write (change) the Stage_Slope and
Stage_Offset terms. The slope is set to 1.00 and the offset to 0.00 at the factory. With the
Stage_Slope set to 1.00 the Stage will be in units of shaft revolutions (1 rev =1.0). The new
values are stored in non-volatile EEPROM within the sensor. Once the new Stage_Slope or
Stage_Offset value is written to the EEPROM, a copy is sent to the sensor data buffer for
verification. This data can be viewed by using a subsequent "D" command. To verify these
settings any other time, use the "XRSS" or “XRSO” commands.
Command Response Description
"aXRSS!" “a0011" Read StageSlope
"aXRSO!" “a0011" Read StageOffset
"aXWSSddd!" “a0011" Write StageSlope
"aXWSOddd!" “a0011" Write StageOffset
Where: a is the sensor address ("0-9", "A-Z", "a-z", "*", "?").
XRSS are upper case characters.
XRSO are upper case characters.
XWSS are upper case characters.
XWSO are upper case characters.
ddd is the new slope or offset value (For example: 20.0 0.195 -500)
This command takes 001 seconds to complete and places 1 value in the data buffer. Use the
“aD0" command to collect and view the slope or offset.
Example of a H-3342 Extended "Read Stage_Slope" command:
Command
Response Time Values Description
"aXRSS!" "a0011" 1 sec 1 Read StageSlope
Command Response Description
"aD0!" "a+1.00" StageSlope is 1.00
Example of a H-3342 Extended "Write Stage_Slope" command:
Command
Response Time Values Description
"aXWSS1.234!" "a0011" 1 sec 1 Write StageSlope
Command Response Description
"aD0!" "a+1.234" StageSlope is 1.234