Sound Devices 722 - Manual (Page 23)

722 User Guide and Technical Information
21
C. Link – Multi-Unit Linking
The proprietary C. Link (control link) connection allows multiple 702, 702T, 722, and 744T record-
ers to be connected and clocked together. C. Link also enables connection to external keyboards and
switch contacts using the CL-1 Remote Control and Keyboard Interface.
When linked, 7-Series recorders have a master/slave relationship. The master recorder and the slave
unit will share sample accurate start and stop record times. Multiple units can be daisy-chained
together to record many tracks. The C. Link protocol links carries the following data:
• word clock
• time code information (702T and 744T only)
• RS-232 machine transport data
master
unit
slave
unit
slave
unit
To link units:
1 . Connect multiple units as shown in the illustration.
2. Set all linked recorders to the same sample rate, bit depth, file format, and time code frame rate (for
702T and 744T recorders). This will ensure that all files generated are compatible.
3. Set scene and take numbers on all linked recorders to the same starting file name. There is no file name
synchronization with multiple unit linking.
When linked, record start and stop on slave units will not affect units “above” it in the linked chain.
This makes it possible for units to get out of synchronization if a unit other than the master is set to
record or stop. Using the master unit will assure that all machines begin and end recording together.
Master/Slave relationships between C.Linked recorders is established immediately after the C.Link
Out to C.Link In connection is made. To reverse the Master/Slave relationship, power down all
recorders, establish the new Master/Slave relationships by reconnecting the C.Link Out to C.Link In
connectors in the desired sequence, then power on all units in order of their Master/Slave relation-
ships
The master recorder in a C.Link connection can not receive wordclock sync from anywhere else. It must
be the master wordclock source for all C.Link slaves.
The C. Link jack is a proprietary RS-232 port. Under no circumstances should analog or digital telephone
lines be connected to either jack. Serious damage could result.