making a opc client in Python and use opc server Events

[getelectronic@gmail.com]

Hi all
I have a sample code to implement opc client in Python. i use a
file .py making by makepy with pythonwin for Com Interface.
i can get all server in machine, connect to server opc, disconnect,
add group, add item, read, write item in server opc.

import win32com.client # librairie pour utiliser l'interface COM/DCOM
from win32com.client import gencache
gencache.Ensure Module('{DFB832 32-A952-11D2-A46B-00C04F796375}', 0, 1,
0)

for svr in opcserver.GetOP CServers():
print svr

#connect to server OPC Demo Simulation from Matrikon
opcserver.Conne ct('Matrikon.OP C.Simulation.1' )

# Instance object Groups
groups=opcserve r.OPCGroups
#add group
group=groups.Ad d('Group1')

#instance onject Items
items=group.OPC Items
# add item in server opc
tem=items.AddIt em('File1.item1 ',1)

#read item value
item.Read(win32 com.client.cons tants.OPCDevice )

# write a new value
item.Write(100)

#read item value
item.Read(win32 com.client.cons tants.OPCDevice )
#if no pb you have 100 :)

#Disconnect
#opcserver.Disc onnect()

BUT, and BUT, i want to use a event from opc server for uodating item
value with this below class. And i don't konw how make it!!!!!!!!
help me plz

opcserver=win32 com.client.Disp atch('OPC.Autom ation.1')
and now i want to use events from opc server. in a class:
class DIOPCGroupEvent :
class DIOPCGroupsEven t:
class DIOPCServerEven t:

[jp.eugster@googlemail.com]

Re: making a opc client in Python and use opc server Events

On 4 juin, 11:32, getelectro...@g mail.com wrote:

Hi all
I have a sample code to implement opc client in Python. i use a
file .py making by makepy with pythonwin for Com Interface.
i can get all server in machine, connect to server opc, disconnect,
add group, add item, read, write item in server opc.
>
import win32com.client # librairie pour utiliser l'interface COM/DCOM
from win32com.client import gencache
gencache.Ensure Module('{DFB832 32-A952-11D2-A46B-00C04F796375}', 0, 1,
0)
>
for svr in opcserver.GetOP CServers():
print svr
>
#connect to server OPC Demo Simulation from Matrikon
opcserver.Conne ct('Matrikon.OP C.Simulation.1' )
>
# Instance object Groups
groups=opcserve r.OPCGroups
#add group
group=groups.Ad d('Group1')
>
#instance onject Items
items=group.OPC Items
# add item in server opc
tem=items.AddIt em('File1.item1 ',1)
>
#read item value
item.Read(win32 com.client.cons tants.OPCDevice )
>
# write a new value
item.Write(100)
>
#read item value
item.Read(win32 com.client.cons tants.OPCDevice )
#if no pb you have 100 :)
>
#Disconnect
#opcserver.Disc onnect()
>
BUT, and BUT, i want to use a event from opc server for uodating item
value with this below class. And i don't konw how make it!!!!!!!!
help me plz
>
opcserver=win32 com.client.Disp atch('OPC.Autom ation.1')
and now i want to use events from opc server. in a class:
class DIOPCGroupEvent :
class DIOPCGroupsEven t:
class DIOPCServerEven t:

Try this:

# Event Handlers
class ServerEvent:
def __init__(self):
print 'Init ServerEvent'

def OnServerShutDow n(self, Reason):
print 'OnServerShutDo wn', Reason

class GroupEvent:
def __init__(self):
print 'Init GroupEvent'

def OnAsyncCancelCo mplete(self, CancelID):
print 'OnAsyncCancelC omplete', CancelID

def OnDataChange(se lf, TransactionID, NumItems, ClientHandles,
ItemValues, Qualities, TimeStamps):
print 'OnDataChange', zip(ClientHandl es, ItemValues, Qualities)

def OnAsyncReadComp lete(self, TransactionID, NumItems, ClientHandles,
ItemValues, Qualities,
TimeStamps, Errors):
print 'OnAsyncReadCom plete', zip(ClientHandl es, ItemValues,
Qualities)

def OnAsyncWriteCom plete(self, TransactionID, NumItems,
ClientHandles, Errors):
print 'OnAsyncWriteCo mplete', zip(ClientHandl es, Errors)

class GroupsEvent:
def __init__(self):
print 'Init GroupsEvent'

def OnGlobalDataCha nge(self, TransactionID, GroupHandle, NumItems,
ClientHandles, ItemValues,
Qualities, TimeStamps):
print 'OnGlobalDataCh ange', zip(ClientHandl es, ItemValues,
Qualities)

opc = DispatchWithEve nts('Matrikon.O PC.Automation.1 ', ServerEvent)

groups = DispatchWithEve nts(opc.OPCGrou ps, GroupsEvent)
groups.DefaultG roupIsActive = True
groups.DefaultG roupUpdateRate = 2000

group1 = DispatchWithEve nts(groups.Add( 'G1'), GroupEvent)
group2 = DispatchWithEve nts(groups.Add( 'G2'), GroupEvent)
#etc ...

It works for the GroupsEvents but I don't get the GroupEvent for each
group, I may still do someting wrong..