handler.rst

Handler

:class:`secsgem.gem.handler.GemHandler` inherits the functionality from :class:`secsgem.secs.handler.SecsHandler` (see :doc:`/secs/handler`).

It automatically handles the whole setup and teardown of the link. Incoming collection events and terminal messages are automatically accepted and propagated by events. The setup of collection event reports is also simplified. It has functionality to send remote commands and handling process programs.

The handler also implements a maintains a communication state, which is defined in the standard.

>>> def on_communicating(event, data):
...     print "Communicating"
...
>>> client = secsgem.GemHandler("10.211.55.33", 5000, False, 0, "test", event_handler=secsgem.EventHandler(events={'handler_communicating': on_communicating}))
>>>
>>> client.enable()
Communicating
>>> client.get_process_program_list()
['test1', 'test2']
>>> client.request_process_program('test1')
This is process program test1
>>> client.disable()

Also streams/functions can be sent and received with the handler:

>>> f = secsgem.SecsS01F01()
>>> client.send_and_waitfor_response(f)
secsgem.hsms.packets.HsmsPacket({'header': secsgem.hsms.packets.HsmsHeader({'function': 2, 'stream': 1, 'pType': 0, 'system': 14, 'sessionID': 0, 'requireResponse': False, 'sType': 0}), 'data': '\x01\x02A\x06EQUIPMA\x06SV n/a'})

Events

GemHandler defines a few new events, that can be received with the help of :class:`secsgem.common.EventHandler`:

Event name	Description
handler_communicating	Connection is setup
collection_event_received	Collection event was received
terminal_received	Terminal message was received