Snell MV-32 - Transactions; Commands

MV-32/64 Multiviewer www.snellgroup.com Hydra Open Protocol
Issue 1 Rev 11 Page 108 © 2014 Snell Limited
A.4 Transactions
A transaction contains a number of commands to be executed by the MV-32/MV-64. It sits
inside a PACKET tag and has the following format:
<TRANSACTION SERIAL=”serial” MODE=”mode”>
…
</TRANSACTION>
serial is a unique string to identify each transaction. The MV-32/MV-64 uses it in the reply to
the transaction. mode is ignored by the MV-32/MV-64 and is not essential (it is just present to
comply with the format of the Hydra Open Protocol).
The result of a transaction is always sent with the following tag:
<TRANSACTIONRESULT SERIAL=”serial” ERROR=”error”>
serial is the same string that was used in the TRANSACTION's SERIAL attribute that was
originally sent to the MV-32/MV-64, and error is the number of commands that have failed due
to errors in the command sent. Within this transaction response, the command results are
stored in the same order that they sent in the original transaction.
A.5 Commands
Each command sits inside a TRANSACTION tag and is of the following format:
<COMMAND ID=”name” SERIAL=”serial”>
…
</COMMAND>
name is the name of the command and serial is a unique string that the MV-32/MV-64 uses in
the command's transaction result. The result of a command sits inside a
TRANSACTIONRESULT tag and is of the following format:
<COMMANDRESULT SERIAL=”serial” ERROR=”error”>
…
</COMMANDRESULT>
error is 0 if the command was successful, non zero if not successful. serial is the serial string
that was supplied in the original COMMAND transaction.
In summary, the complete format of a command transaction XML document is:
<XML>
<PACKET MODULE=”MV-32/MV-64” VERSION=”1.0”>
<TRANSACTION SERIAL=”serial” MODE=”mode”>
<COMMAND ID=”name” SERIAL=”serial”>
…
</COMMAND>
…more <COMMAND> and </COMMAND> tags if more than one command is to be sent
</TRANSACTION>
</PACKET>
</XML>