The NodeOPCUA API
TCP_transport Class
TCP_transport
Constructor
TCP_transport
()
Item Index
Methods
- _install_one_time_message_receiver install a one time message receiver callback Rules: * TCP_transport will not emit the ```message``` event, while the "one time message receiver" is in operation. * the TCP_transport will wait for the next complete message chunk and call the provided callback func ```callback(null,messageChunk);``` * if a messageChunk is not received within ```TCP_transport.timeout``` or if the underlying socket reports an error, the callback function will be called with an Error.
- _install_socket
- createChunk
- disconnect
- write
Properties
Events
Methods
_install_one_time_message_receiver
install a one time message receiver callback
Rules:
* TCP_transport will not emit the ```message``` event, while the "one time message receiver" is in operation.
* the TCP_transport will wait for the next complete message chunk and call the provided callback func
```callback(null,messageChunk);```
* if a messageChunk is not received within ```TCP_transport.timeout``` or if the underlying socket reports an error,
the callback function will be called with an Error.
-
callback
Parameters:
-
callbackFunctionthe callback function
-
errNull | Error -
messageChunkBuffer | Null
-
_install_socket
-
socket
Parameters:
-
socketSocket
createChunk
-
msg_type -
chunk_type -
length
createChunk is used to construct a pre-allocated chunk to store up to length bytes of data.
The created chunk includes a prepended header for chunk_type of size self.headerSize.
Parameters:
-
msg_typeObject -
chunk_typeStringchunk type. should be 'F' 'C' or 'A'
-
lengthObject
Returns:
a buffer object with the required length representing the chunk.
Note:
- only one chunk can be created at a time.
- a created chunk should be committed using the
writemethod before an other one is created.
disconnect
-
callback
disconnect the TCP layer and close the underlying socket.
The "close" event will be emitted to the observers with err=null.
Parameters:
-
callbackObject
write
-
message_chunk
write the message_chunk on the socket.
Parameters:
-
message_chunkBufferNotes:
- the message chunk must have been created by
createChunk. - once a message chunk has been written, it is possible to call
createChunkagain.
- the message chunk must have been created by
Properties
[timeout=30000]
Number
timeout
chunkReadCount
Number
chunkWrittenCount
Number
headerSize the size of the header in bytes
Number
Default: 8
protocolVersion indicates the version number of the OPCUA protocol used
Number
Default: 0
Events
close
notify the observers that the transport layer has been disconnected.
Event Payload:
-
errObjectthe Error object or null
message
notify the observers that a message chunk has been received
Event Payload:
-
message_chunkBufferthe message chunk
socket_closed
notify the observers that the transport layer has been disconnected.
Event Payload:
-
errObjectthe Error object or null