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Daisy-chain Features
All of the features described in Chapter 5 are available in daisy-chain operation
with a Polling Controller; however, the function of priority modes (Emergency,
Total, and No Priority) is slightly different.
Note:
For information on changing the proprietary defaults for transfer codes
in daisy-chain applications, please refer to the tables in Chapter 3.
For the following explanation, assume that three SLSS units are being
daisy-chained as indicated in the illustration.
In order to use Emergency Priority, program the last SLSS in the chain for
Emergency Priority and all others for Total Priority. The last SLSS in the chain
will have priority over all others in the chain. When an emergency call is made,
the Total Priority mode of other units up the chain will cause any call in progress
to be terminated. As soon as dial tone is received from the PSTN, the emergency
call will be processed.
If you assign Total Priority to all SLSS units in the chain, devices connected to
ports on the first and second SLSS will be disconnected if any port on the last
SLSS goes off-hook.
Caution:
If one of the SLSS ports is in use when you go off-hook in either Total or
Emergency Priority Mode, the SLSS will be unable to obtain network dial tone until
the call disconnects or until the PSTN times out (usually within 10-15 seconds).
If you assign No Priority to any of the SLSS units, calls will never be interrupted.
This setting is not advised for applications requiring a telephone in emergency
situations.
Reference Manual
Chapter 7: Daisy-chain Operation
40-400-00031, Rev. A
Page 47