User guide

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Serial port switching
The AdderLink AV204T and AV208T modules use a sophisticated switching
system to extend the ordinarily point-to-point nature of serial communications
across a network of connected display units. The AdderLink system allows you
to communicate with any display individually or to broadcast commands across
the network as a whole. When switching to a single display, it is then possible
toreceiveresponsesbackfromthatdisplay.When‘broadcasting’toall,itisonly
possibletosendcommandsinauni-directionalmanner(suchas‘on’and‘off’).
AsimplesystemofASCIIcommandsisusedtoeffecttheswitching.Youcan
issuesuchcommandsdirectlyviaanASCIIconsoleoruseautilitysuchasthe
AdderDisplayManagertoprovideanintuitivegraphicalinterface.Oncea
switching command is issued, the network will remain fixed at that setting until
a new command is sent, therefore there is no need to precede every RS232
command with a header sequence.
Port switching commands
TheASCIIportswitchingcommandstructureisasfollows:
<AV PORT 27B>
<AV PORT 14A>
TRANSMITTER
1
2
2
3
4
5
6
8
RECEIVER
A
B
Primary
Transmitter
TRANSMITTER
1
1
2
3
5
6
7
8
RECEIVER
A
B
14A
14B
27A
27B
4
7
<AV PORT>
CPD
Cascade
[1 to 4]
Port
[1 to 8]
Display
[A, B or X]
Note: The command must use
capital letters and there must be
a space between ‘AV’ and ‘PORT’,
and also between ‘PORT’ and the
cascade number.
The primary transmitter is
automatically numbered as
Cascade 1, with successive
cascaded transmitters taking
numbers 2 to 4. The Port
number is determined by the
link cable port on the transmitter
to which a given receiver is
connected. The Display character
is determined by which of the
Y-cable connectors is used (X
opens a one-way link to both
displays).IfnoY-cableisused,a
single display will be A.
To connect with all displays, issue
the following command:
<AV PORT ALL>
Module switching commands
Inadditiontoaffectingindividualports,itisalsopossibletocollectivelyenable
and disable all of the CATx outputs from a particular transmitter (at power
on, all CATx outputs are enabled by default). Disabling the outputs of one
transmitter will not affect the operation of other transmitters that are cascaded
through the disabled module.
To disable all CATx outputs on a transmitter:
<AV DISABLE n> where n is the transmitter number (1, 2, 3 or 4)
To enable all CATx outputs on a transmitter:
<AV ENABLE n> where n is the transmitter number (1, 2, 3 or 4)