RFL SMX3 / 21
Page 15 of 22
Issue 1.4
User Manual
08 June 2009
DIP Switch 2 – 3 settings:
SW 2 V.24 Data Channel B Configuration SW3 – V.24 Channel C Configuration
8 7 6 5 4 3 2
1
Baud Rate
Route
Mode
Agg Channel
Assignment
00 = 1200
00 = via X.21 Agg. Port
00 = Disabled
00 = Ch 2
01 = 2400
01 = via Concat. Port
01 = Transparent
01 = Ch 3
10 = 4800
10 = Both Ports
10 = Async 8 bit
11 = 9600
11 = Local Loop
11 = Async 9 bit
•
Channel Allocation and Sharing: Select aggregate channel 2 or 3
Each V.24 Data Channel can be allocated to Aggregate Channel 2 or 3. More than
one port may share a channel.
Where more than one Data Channel is allocated to the same Aggregate Channel, the
ports share the aggregate channel. From the point of view of one of those ports,
Transmit Data would be sent over the aggregate channel and to all other ports
allocated to the same channel. Data from the aggregate channel or other such port(s)
would appear as Received Data. This feature is useful for supporting SCADA
systems where multiple terminals are attached, but they must be well disciplined
where only one terminal transmits at once, waiting for CTS after asserting RTS.
•
Mode: Disabled, Transparent, Async 8 bit, Async 9 bit.
Transparent is used where end-to-end delay is critical and may also be used for
applications where asynchronous character formats are not specifically supported.
The baud rate settings are ignored. (See section 5)
Async 8 bit is selected for:
7 data bits plus 1 parity bit (even or odd).
or:
8 data bits plus 0 parity bit.
Async 9 bit is selected for:
8 data bits plus 1 parity bit (even or odd).
•
Route: X.21 Port, Concatenation Port, Both Ports.
If X.21 Port is selected, traffic on the allocated aggregate channel terminates at this
port. That channel is then available for other traffic over the Concatenation Port.
If Concatenation Port is selected, data on the selected aggregate channel terminates
at this port and that channel is available for other data over the aggregate.
If Both is selected, traffic on the selected aggregate channel between X.21 Port and
Concatenation Port appears at RxD as an 'or' of data from either direction, and TxD is
sent in both directions. This mode is suitable only for a well-disciplined system
(where only one terminal transmits at once), waiting for CTS after asserting RTS.
Local Loop operates as described for DIP Switch 1
As channels B and C are asynchronous there is no requirement for a network clock.
•
Baud Rate: 1200, 2400, 4800, 9600 bits/sec.
When Async 8 or Async 9 mode is selected, set the baud rate to match the
connected equipment. 9600 bits/s requires allocation to a 32kHz sampling channel.
Do not
set different baud rates for ports allocated to the same aggregate channel.
