Paradise Datacom P300 Series Installation & Operating Handbook page 80

Normal 8k synchronous access is provided on the ESC port.
This option is only available of the Async ESC feature is available (standard on
P300-IBS and above). The ESC interface is set to be asynchronous. The exact
Baud rate it can support varies with the async character format set on the
Async ESC menu. Typically with 8 bits per character (or 7 + parity) it will
support 4800 Baud, but with 8 bits plus parity, it will operate to 9600 Baud.
The reason for this strange situation is as follows: The async data is carrier
synchronously across the 8k ESC link at 9 sync bits per async character (start
+ 8 data bits, no stop or parity). At 9600 Baud with 8 bits/char there are a
maximum of 960 async characters per second (9600 / 10 [start + 8 bits + stop]).
960 async characters per second requires 9 x 960 sync bits per second to
convey, unfortunately 8.64kbps above the 8kbps channel capacity and so
characters will be lost. At 9600 Baud with 9 bits/char (ie 8 plus parity) there are
872 async characters per second (9600 / 11 [start + 8 bits + parity + stop]). 872
async characters per second requires 9 x 872 sync bits per second to convey,
7.85kbps, and so no characters will be lost over the 8K ESC channel. So when
set for [8 bits No Parity] or [7 bits with Parity] the maximum standard Baud rate
is 4800 Baud. When set for [8 bits with Parity] the maximum standard Baud
rate is 9600 Baud.
This is followed by the Aux port definition screen:
1=Off (normal) 2=64K in V1&2 3=32K in V1 4=32K in V2
Change, Tx/Rx, ESC/Aux/BA, Define (IDR), Aux Menu
The Aux port can provide a 32kbps or 64kbps synchronous data circuit in place of one or both of the
Audio ESC channels:
The Audio ESC channels operate as normal, the Aux port is disabled.
Both ESC Audio channels are disabled, and the Aux port operates at 64kbps.
Audio ESC V2 operates as normal, and the Aux port provides a 32kbps
channel in V1.
Audio ESC V1 operates as normal, and the Aux port provides a 32kbps
channel in V2.
P300H P300 Series Modem Installation and Operating Handbook
Tx Aux Circuit: [?]
Page 80