Using the DM24
transmitted in real-time where possible, but are worried about possible breaks in
communication, you should use
ADAPTIVE
mode instead.
FIFO
mode will consider a data block successfully transmitted once it has received
an acknowledgement from the next device in the chain. If there are several devices
between you and the instrument, you will need to set up the mode for each device (if
applicable) to ensure that data flow works the way you expect.
Like all the transmission modes,
FIFO
mode does not delete data once they have
been transmitted. You can still request anything in the Flash memory using Scream!
or over the command line. The only way data can be deleted is if they are
overwritten (in the
RECYCLE
buffering mode, see below) or if you delete them
manually.
4.3.5.1 ADAPTIVE
Command:
ADAPTIVE
Instructs the DM24 to transmit current blocks to clients if possible, but to store all
unacknowledged blocks in the Flash memory and re-send them, oldest first, when
time allows.
ADAPTIVE
mode is best suited for “real-time” installations where the
link between digitiser and client is intermittent or difficult of access.
If the communications link is only marginally faster than the data rate, it will
usually be busy transmitting real-time data. Thus, it may take a while for the
instrument to work through the missed blocks. In this case, and if your client
supports it, you may prefer to use the Block Recovery Protocol to request missed
blocks where possible (see section 8.3 on page 118).
Some software packages (most commonly Earthworm) cannot handle blocks being
received out of time order. If you are using such a package,
ADAPTIVE
mode will not
work and may crash the software.
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Issue U - December, 2021