Hi Monks,

Has anyone per chance worked at all with OPC & perl? Specifically the package Win32::OLE::OPC. I'm having a mare of a time with it. My latest problem is writing data, here's the relavent code:

    my $itemdata = OPCItemRead ($rightdata[0], $i+1);
    $rightdata[0]->{lastvalues}->[$i] = $itemdata->{Value};
    OPCItemWrite($rightdata[0], $i+1, $rightdata[0]->{lastvalues}->[$i
+] + 1);
[download]

And the subs

sub OPCItemRead {

    my $groupdata = shift;
    my $itemno = shift;
    
    my $items;
    my $data;                                    # reference to the ha
+sh of data returned by Read()
    
    $items = $groupdata->{grouphandle}->OPCItems();

    $data = $items->Item($itemno)->Read($OPCDevice);
    
}

sub OPCItemWrite {

    my $groupdata = shift;
    my $itemno = shift;
    my $newvalue = shift;
    
    my $items;
    
    $items = $groupdata->{grouphandle}->OPCItems();

    $items->Item($itemno)->Write($newvalue);
    
}
[download]

The read function works absolutely fine, the write always gives:

OPC::Item::Write Matrikon.OPC.DDE:
    Win32::OLE(0.1707) error 0x80070057: "The parameter is incorrect"
    in METHOD/PROPERTYGET "Write"
 at C:/Program Files/Perl/lib/Win32/OLE/OPC.pm line 1666
[download]

If I stop the debugger in the write function just before the write $groupdata, $itemno and $newvalue all look fine. If I do this

x $items->Item($itemno)->Read($OPCDevice)
[download]

I get the expected data hash so I'm sure everything is set up correctly. As soon as I execute the write up pops this more verbose version of the same error:

OPC::Item::Write Matrikon.OPC.DDE:
    Win32::OLE(0.1707) error 0x80070057: "The parameter is incorrect"
    in METHOD/PROPERTYGET "Write"
 at C:/Program Files/Perl/lib/Win32/OLE/OPC.pm line 1666
 at C:/Program Files/Perl/lib/Win32/OLE/OPC.pm line 123
        Win32::OLE::OPC::_check_error('OPC::Item::Write Matrikon.OPC.D
+DE') called at C:/Program Files/Perl/lib/Win32/OLE/OPC.pm line 1666
        Win32::OLE::OPC::Item::Write('Win32::OLE::OPC::Item=HASH(0x22c
+2360)', 11) called at opccompare.pl line 542
        main::OPCItemWrite('HASH(0x2291d14)', 5, 11) called at opccomp
+are.pl line 151
main::(opccompare.pl:154):                              if (not($debug
+ =~ m/quiet/)) {
[download]

All the man for this method says is

<b>Write(VALUE)</b>
     Write VALUE to this item.
[download]

So taking the error message at face value perhaps I'm expressing VALUE incorrectly. I've tried passing a ref to the data instead of the data value and it makes no difference. I've tried a bare value, a quoted value and a double quoted value. I've tried using a hash like the Read() returns or a ref to that hash. Apart from Swahili, Sanskrit or Welsh I've expressed VALUE in every way I can think of. Here's an online version of the help http://www.opcconnect.com/perl/OPC.html#opcitem

The example supplied with the package, groups.pl, gives exactly the same error for writes. Any monks in the monestary familiar with OPC?

Cheers
nonk

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