Asynchronous Channels - Vocality V100 Technical Manual

Field Options
TX CLOCK RATE 50-2048000bps
TX CLOCK SOURCE Ext,
Rxc,
PLL,
Int,
Dba
DESTINATION "NODE:SLOT:CHANNEL",
LOOP,
ECHO,
SWITCHED,
SCADA
BTXnnn,
BRXnnn,
BTRttt,rrr"
3.4.6.1

Asynchronous Channels

Asynchronous operation is configured simply by selecting an async format from the menu. When a
channel is configured to operate with an asynchronous format, the TXC fields are removed and only a rate
and a reference field are displayed. An additional single-character FORMAT field is displayed to the right of
the normal field which allows the user to select (R)aw, (E)rror-corrected or (C)ompressed mode for data
transfer. (See section 4.10)
It is permissible to operate aggregate channels in asynchronous mode as well as tributaries. The reference
field is not required for tributary operation and should be left set to "-"; if the channel is an aggregate
then the selected rate may be used to drive the GRX reference by configuring the clocking menu. In this
way, synchronous tributaries and voice channels may still be used successfully over an async aggregate,
although they cannot be phase–locked between chassis.
Asynchronous tributary channels will pass data characters in and out of the port at the specified rate.
Internally however, they use bandwidth from the Dynamic Pool; this means that when they are
temporarily inactive, all but 2400bps of their bandwidth can be given back to the pool for use by other
channels. Before a channel fills up with data to the limit of its buffers, the channel CTS signal is
disaffirmed to the connected equipment as a means of hardware flow control. For details of how async
channels operate internally, refer to the Dynamic Bandwidth Allocation (DBA) section 4.5.
V100 Versatile Multiplexer Technical Manual Version 2.2
C H A P T E R
Description
Transmit clock bit rate. This may be set at any
rate from
50 to 2048000bps (synchronous) or
50 to 115200bps (asynchronous)
TX clock input from the interface
TX clock output, looped from RX
TX clock output, derived from PLL
TX clock output, phase-locked from system clock
Dynamic Bandwidth Allocation (output)
Data will only be transmitted to the designated
port
Port TX data is internally looped to RX
Port RX data is internally looped to TX
Aggregate link requested by RTS flag
Aggregate link uses SCADA protocol
Broadcast TX channel number
Broadcast RX channel number
Broadcast TX and RX channel numbers
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