Vaisala WMT700 - Manual (Page 171)

Chapter 5 _________________________________________________________________ Operation
a! — Acknowledge Active
This command ensures that WMT700 is responding to a data
recorder or another SDI-12 device. It asks the WMT700 to
acknowledge its presence on the SDI-12 bus.
a!
where
a = Single-digit WMT700 address that corresponds to the
first character of the address value
! = Terminates the command
The response is the following:
a<CR><LF>
where
a = Single-digit WMT700 address that corresponds to the
first character of the address value
<CR><LF> = Terminates the response
Example of the command and response:
1!
1<CR><LF>
VAISALA _______________________________________________________________________ 169