Guralp Systems CMG-CD24 - Manual (Page 42)

CMG-CD24
If you prefer, you can use the CD24 terminal to switch between
transmission modes. The commands to use, which take effect
immediately, are given below.
3.2.5.1 DIRECT
Syntax: DIRECT
Instructs the digitizer not to use Flash memory for storage. Instead, all
data is transmitted directly to clients. A digitiser in DIRECT mode still
honours the GCF Block Recovery Protocol: a temporary RAM buffer
always holds the last 256 blocks generated, and if a client fails to
receive a block it can request its retransmission.
If you expect breaks in communication between the digitiser and its
client to last more than 256 blocks, or if you want the digitiser to
handle breaks in transmission (rather than relying on the client to
request missed blocks), you should use
•
ADAPTIVE mode, if you want data to stay as near to real time as
possible (but do not mind if blocks are received out of order) or
•
FIFO mode, if you need blocks to be received in strict order (but
do not mind if the digitiser takes a while to catch up to real
time.)
3.2.5.2 FILING
Syntax: FILING
Instructs the CD24 not to transmit blocks to clients automatically, but
to store all digitised data in the Flash memory. If you have chosen the
RECYCLE buffering mode (see below), the memory is used in circular
fashion, i.e. if it becomes full, incoming blocks begin overwriting the
oldest in memory. If the WRITE-ONCE mode is active, the digitiser
will switch to DIRECT mode (see above) when the memory becomes
full.
42 Issue C