MV-32/64 Multiviewer
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Hydra Open Protocol
Issue 1 Rev 11
Page 107
© 2014 Snell Limited
Appendix A. Hydra Open Protocol
A.1 Introduction
The MV-32/MV-64 contains a selection of the commands defined in the Barco Hydra Open
Protocol. They have been adapted to control the MV-32/MV-64 in as close as possible way as
they would control a Hydra, with the aim being to enable existing scripts already used with a
Hydra to be utilized. This protocol uses XML to control certain features of the MV-32/MV-64 in
a user-friendly way on a LAN or through the serial port.
A.2 Formatting
All messages sent to and received from the MV-32/MV-64 use XML formatting, with each
message enclosed in the tag XML. The first element inside the XML tag is always PACKET.
The structure is always of the format:
<XML>
<PACKET MODULE=”MV-32/MV-64” VERSION=”1.0”>
…
</PACKET>
</XML>
The
MODULE
and
VERSION
attributes in the
PACKET
element are not essential - they are
simply there to comply with the Hydra Open Protocol, but are ignored by the MV-32/MV-64.
The response to this will be the same.
A.3 Connections
The Hydra Open Protocol has two types of connections - one for transactions and one for
event handling. However, the MV-32/MV-64 currently only supports transaction types. This is
done using TCP port 8881. The normal procedure for sending transactions is:
•
Connect using TCP port 8881 to the MV-32/MV-64
•
Send a transaction as XML formatted text
•
Receive the result of this transaction as XML formatted text
•
Repeat this procedure for further transactions. The connection can be kept open for
as long as necessary.
•
Close the socket when finished.
The procedure for sending transactions using the serial port is the same, except that the TCP
socket connection is not applicable.
If the serial port is to be used then the multiviewer's serial port needs to be configured to use
the Hydra Open Protocol option in the Module menu -> Setup Module -> Protocols tab. For
controlling over ethernet, no configuration needs to be done - the MV is always listening on
port 8881 for a connection to be established.
