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SDI-12 COMMAND &
RESPONSE PROTOCOL
A
is an upper-case ASCII character.
n
is the new sensor address to be programmed ("0-9", "A-Z", "a-z", "*", "?").
NOTE: To verify the new address use the "Identify Command."
Example of a "Change Sensor Address" command:
Command
"aA2!"
Zero the Position Command
The "Zero Position" command resets the encoder position counter internal to the H-3301/3311.
This allows for maximum counting range in both the clockwise and counter-clockwise directions.
When the H-3301/3311 is first powered up the position count is automatically reset to zero. After
the unit has been powered up for some time, the Zero Position command provides a means to
reset the position counter.
In most applications the initial position count will be at some undetermined value due to moving
the encoder or adjustment of the float cables. Before programming the offset term (b) of the
mX+b data scaling equation it is important to zero the current position count. This preserves the
maximum dynamic range of the H-3301/3311's 16-bit position counter(±32768 raw counts). After
the position counter is zeroed, program the mX+b equation to obtain the desired stage using the
extended write offset command ("aXWO".)
Command
"aXZ!"
Where:
a
is the sensor address ("0-9", "A-Z", "a-z", "*", "?").
XZ
are upper case characters
This command takes 000 seconds to complete and places no data in the data buffer.
Example of an Extended "Zero the Position" command:
Command
"aXZ!"
18
Response
"2<cr><lf>"
Response
"a<cr><lf>"
Response
"a<cr><lf>"
Description
Change sensor address to "2"
Description
Zero the position counter
Description
Reset encoder position
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