Send identification command (ai!), Address query command (?!) – Vaisala WS425 User Manual
Page 56

USER'S GUIDE____________________________________________________________________
56 __________________________________________________________________ M210361EN-E
Send Identification Command (aI!)
This command is used to query sensors for their SDI-12 compatibility
level, model number, and firmware version number.
The following is an example of the command:
aI!
where
a
=
The sensor address.
I
=
The send identification command
!
=
Terminates the command.
The following is an example of the response:
allccccccccmmmmmmvvvxxx . . . xxx
where
a
=
The sensor address.
ll
=
The SDI-12 version number, indicating
SDI-12 version compatibility; for example,
version 1.1 is encoded as 11.
cccccccc
=
An 8-character vendor identification Vaisala_
mmmmmm =
6
characters
specifying the sensor model number
WS425.
vvv
=
3 characters specifying the firmware version
604.
For example,
xxx ... xx
=
An optional field, up to 13 characters, used for a
serial number or other specific sensor
information that is not relevant for operation of
the data recorder (not used).
=
Terminates the response.
Address Query Command (?!)
When a question mark (?) is used as the address character with the
acknowledge active command (a!), the sensor will respond as if it is
being addressed on the SDI-12 bus. For example, if a sensor detects ?!, it
will respond with a
,
no matter what its address may be. This
will allow a user to determine the address of a sensor. The user should
understand that if more than one sensor is connected to the bus, they will
all respond, causing a bus contention.