Townshend Computer Tools DAT-Link - Synchronization with DAT-Link Versions Prior to 1.6

82 Using Multiple DAT-Links
The two rst lines instruct b oth units to receive their clo ck from an external source.
By p erforming this setup before running the naplay commands, all the clocks will
have stabilized before output b egins. Next, playback is started on unit 0. However,
playback will not actually commence until both unit 0 and unit 1 both indicate
they are ready by releasing the READY signal on the Sync connector. This occurs
only after the fourth line is executed and the playback of le0 and le1 begin
simultaneously.
To record from two DAT-Link +'s with the recordings starting simultaneously, the
following commands can b e used:
narecord -u :0 file0 &
narecord -u :1 file1
Note that since the data is self-clocking, only start-time synchronization is p er-
formed in this case.
There are no intrinsic limits on how many units can b e synchronized using the above
techniques. However, using multiple netaudiod servers and naplay or narecord
processes can quickly overload the host computer. Typically, if full-bandwidth,
stereo signals are being used, only two or three units can be synchronized using
these techniques b efore the host computer is unable to keep up with the data ow.
To record or playback les using a greater number of units, the dlmrec or dlplay
programs describ ed b elow should be used.
9.1.2 Synchronization with DAT-Link Versions Prior to 1.6
When multiple DAT-Links are used it may be necessary to generate output at
exactly the same rate on each unit. This can be done using the External Clock
input/output connector on the rear of each DAT-Link . A BNC cable can b e used
to connect together the DAT-Links . Then, one DAT-Link can be used as a master
clock source and the other units can b e slaved o the master. This clock can also
be used to trigger playback and recording.
For example the following commands will play le1 and le2 on two DAT-Links
connected to the host named foo at the same sampling rate using unit 0 as the
master and unit 1 as a slave.
naset -u foo:0 -S E
naset -u foo:1 -S E
naplay -u foo:0 -S E44100 file1 &
naplay -u foo:1 -S E44100 file2 &
naset -u foo:0 -S OG
By making both units slaves neither unit will have a clo ck source, and no output
will be produced. When unit 0 is changed to a master clo ck source by the last line