Xylem H-335 - Manual (Page 26)

2-10 SDI-12 Command and Response Protocol H-335
Example of a H-335 Extended "Read Coefficient" command:
Command Response Time Values Description
"aXRC3!" "a0011" 1 sec 1 Read Coefficient 3
(gate radius)
Subsequent Command Response
"aD0" a+36.000
2.10 Extended “Read Coefficient” Command
The H-335 processes the sensor measurement data with a set of coefficients. Each coefficient is
programmable, allowing the H-335 to be used on gates with different geometries, and to scale the
height and distance output values to user desired engineering units. This command allows the user
to read any of the coefficients. At the factory the coefficients are set to the following values.
Coefficient Default Value Description
C1 +1.0 User angle slope (compensates for clockwise or counter-
clockwise mounting )
C2 0.0 User angle offset (provides zero output with gate against sill)
C3 36.0 (Feet) Gate Radius (determines user units; inches, feet etc.)
C4 51.05756 Degrees Sill Angle (angle of the gate sill with respect to trunnion
bearing)
Command Response Description
"aXRCn!" "a0011" Read Coefficient
Where:
a is the sensor address ("0-9", "A-Z", "a-z", "*", "?").
XRC are upper case characters
n is coefficient number 1 to 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 data.