Win32::OLE::OPC - OPC Server Interface
Two ways of using the OPC interface are provided, the class methods:
use Win32::OLE::OPC;
my $opcintf = Win32::OLE::OPC->new('Someones.OPCAutomation',
'Someones.Server');
$opcintf->MoveToRoot;
foreach $item ($opcintf->Leafs) {
print $item->{name}, "\n";
my %result = $opcintf->ItemData($item->{itemid});
for $attrib (keys %result) {
print " [", $attrib, " = '", $result{$attrib}, "']", "\n";
}
print "\n";
}
foreach $item ($opcintf->Branches) {
print $item->{name}, "\n";
}
or a tied hash:
use Win32::OLE::OPC;
my %OPC;
tie %OPC, Win32::OLE::OPC, 'Someones.OPCAutomation', 'Someones.Server';
# OK, list the keys...
for $key (keys %OPC) {
my %x = %{$OPC{$key}};
print $key, "\n";
for $attrib (keys %x) {
print " '", $attrib, "' = '", $x{$attrib}, "'", "\n";
}
print "\n";
}
The tied hash method has to return a reference to a hash containing the item
data hence the unpleasant code '%x = %{$OPC{$key}}'. Alternatively one can
assign the returned value into a scalar and dereference it when using the hash
like this 'keys %$x' and '$result->{$item}'.
Note that both methods can be used together. First create an interface using the new() method and then tie it like this:
tie %OPC, $opcintf, 'Someones.OPCAutomation', 'Someones.Server';
To connect to a remote server add the name of the server as a parameter to the
call to new() or to the tie:
my $opcintf = Win32::OLE::OPC->new('Someones.OPCAutomation',
'Someones.Server',
'machine.name');
tie %OPC, Win32::OLE::OPC, 'Someones.OPCAutomation',
'Someones.Server',
'machine.name';
A partial implementation of the OLE for Process Control dispatch interface as defined in the 'Data Access Automation Interface Standard' version 2.
An exception is raised using Carp::croak() on any failure.
new() method creates an instance of an OPC server object. The
DLLPROGID argument is the COM progid of the Dll which implements the Dispatch
interface to the OPC server. The SERVERPROGID is the COM progid of the OPC
server containing the data you wish to access. The DLLPROGID and SERVERPROGID
arguments are required.
The SERVERNODE argument is optional and is the name of a remote machine running the SERVERPROGID. When SERVERNODE is specified a connection is made to the server using DCOM. WARNING: DCOM security can be a little difficult to understand so perseverance is required.
As the OPC specification only allows one browser per instance of the dispatch
Dll the new() method creates and keeps a browser object in
Win32::OLE::OPC->{browser}
MoveDown(TO)TO parameter is the branch name.
MoveTo(TO)TO.
$opcintf->MoveTo('COM1._Diagnostics');
Returns the branch names and itemid in a hash in an array. The method has a different name from the OPC ShowBranches method because it doesn't do quite the same thing.
The returned array is also stored in Win32::OLE::OPC->{items}.
See synopsis for an example of how to call this method.
Returns the leaf names and itemid in a hash in an array. The method has a
different name from the OPC ShowLeafs because it doesn't do quite the same
thing. The hash has the members name and itemid. The number of items
in the array is saved in Win32::OLE::OPC->{count}
The returned array is also stored in Win32::OLE::OPC->{items}.
foreach $item ($opcintf->Leafs) {
print $item->{name}, " ", item->{itemid}, "\n";
}
Item(N)N. Calls to
Leafs and Branches collect the item data. This is an alternative method
of fetching the address space.
$opcintf->Leafs;
for (my $i = 0; $i < $opcintf->{count}; $i++) {
my $item = $opcintf->Item($i);
print $item->{name}, " ", item->{itemid}, "\n";
}
ItemData(ITEMID)ITEMID is the itemid member of the hash returned by the Leafs
method.
It returns a hash, the keys of which are the available attributes (found by
calling the OPC QueryAvailableProperties() method) and the values of in the
hash are obtained by calling GetItemProperties.
AvailableProperties(ITEMID)ITEMID is the itemid
member of the hash returned by the Leafs method.
It returns an array of hashes containing the available attributes found by
calling the OPC QueryAvailableProperties() method. The hash contains
Id, Description and DataType members.
The returned array is also stored in Win32::OLE::OPC->{properties}.
print " Id Type Description\n";
foreach my $prop ($opcintf->AvailableProperties($item->{itemid})) {
printf "%3d %4d %s\n",
$prop->{Id},
$prop->{DataType},
$prop->{Description};
}
StartTime CurrentTime LastUpdateTime MajorVersion
MinorVersion BuildNumber VendorInfo ServerState LocaleID
Bandwidth OPCGroups PublicGroupNames ServerName
ServerNode ClientName
Note that the OPCGroups value is itself a reference to a hash and it contains a hash member indexed 'Parent' which is a hash pointing back up.
use Win32::OLE::OPC qw(GetOPCServers);
my @AvailableServers = GetOPCServers('Someones.OPCAutomation');
Organization Filter DataType AccessRights CurrentPosition Count
See the SYNOPSIS for example code.
If you tie a hash to this module you can:
keys and each function will
work.
Writing, deleting or undefining a member of the hash is not possible.
The Win32::OLE::OPC::OPCGroups method returns an OPCGroups object which is blessed into the perl Win32::OLE::OPC::Groups class.
Parent DefaultGroupIsActive DefaultGroupUpdateRate DefaultGroupDeadband DefaultGroupLocaleID DefaultGroupTimeBias Count
Note that the hash member indexed 'Parent' is a hash pointing back up to the parent properties.
SetProperty(PROPERTY,VALUE)DefaultGroupIsActive DefaultGroupUpdateRate DefaultGroupDeadband DefaultGroupLocaleID DefaultGroupTimeBias
Add(NAME)GetOPCGroup([SERVERHANDLE|NAME])Remove([SERVERHANDLE|NAME])ConnectPublicGroup(NAME)This is untested as I have no server which implements public groups.
RemovePublicGroup([SERVERHANDLE|NAME})This is untested as I have no server which implements public groups.
The Win32::OLE::OPC::Group object has methods Add, Item, GetOPCGroup and ConnectPublicGroup which all return a hash blessed into the OPCGroup class.
Parent Name IsPublic IsActive IsSubscribed ClientHandle ServerHandle LocaleID TimeBias DeadBand UpdateRate OPCItems
Note that the hash member indexed 'Parent' is a hash pointing back up to the parent properties.
SetProperty(PROPERTY,VALUE)Name IsActive IsSubscribed ClientHandle LocaleID TimeBias DeadBand UpdateRate
SOURCE is source of data. NUM is how many. SERVERHANDLES is a reference to an array of server handles. VALUES is a reference to an variant array to hold item values. ERRORS is a reference to an array to hold error codes.
This class contains a collection of OPCItem objects.
Parent DefaultRequestedDataType DefaultAccessPath DefaultIsActive Count
Note that the hash member indexed 'Parent' is a hash pointing back up to the parent properties.
SetProperty(PROPERTY,VALUE)DefaultRequestedDataType DefaultAccessPath DefaultIsActive Count
Item(NUMBER])GetOPCItem(SERVERHANDLE)NUM is how many. ITEMIDS is a reference to an array of itemids. CLIENTHANDLES is a reference to an array of client handles. CLIENTHANDLES is a reference to an array of client handles. SERVERHANDLES is a reference to an array to hold server handles. ERRORS is a reference to an array to hold error codes.
This is the object used for reading and writing actual values.
Parent ClientHandle ServerHandle AccessPath AccessRights ItemID IsActive RequestedDataType Value Quality TimeStamp CanonicalDataType
Note that the hash member indexed 'Parent' is a hash pointing back up to the parent properties.
Read(SOURCE)Read returns a hash reference which contains Value, Quality and TimeStamp values.
Write(VALUE)
If you have nmake you can use MakeMaker as follows:
perl Makefile.PL nmake nmake test nmake install nmake documentation
The final step makes OPC.html and OPC.txt from OPC.pm.
If you don't have nmake then you will find OPC.html and OPC.txt are included
in the package ready built and all you have to do is copy OPC.pm into the
site/lib/Win32/OLE directory with your Perl installation. This module has
been tested with ActiveState Perl build 522.
(c) 1999,2000,2001,2002 Martin Tomes. All rights reserved.
Developed by Martin Tomes <martin@tomes.freeserve.co.uk>.
(c) 2004 Modified by Karl Scherer. Mods to AddItems and $items->Remove.
Added SyncRead methode to group object
<scherer@hotmail.com, scherer@gene.com>.
You may distribute under the terms of the Artistic License. See
LICENSE.txt
Martin Tomes, martin@tomes.org.uk
Version 1.01