Powershell opc xml write UInt32 array - powershell

Question

I've managed to read an OPC XML item with a Powershell script
$wsdl=(Join-path $PSScriptRoot "OpcXmlDa1.00.wsdl")
$global:Proxy = New-WebserviceProxy $wsdl –Namespace X
$global:Options = New-Object X.RequestOptions
$Options.ReturnItemName = $true;
$Options.ReturnItemTime = $true;
$global:ItemList = New-Object X.ReadRequestItemList
$global:RItemList = New-Object X.ReplyItemList
$global:Errors = New-Object X.OPCError
$global:Item = New-Object X.ReadRequestItem
# Read from OPC server
$Proxy.Url = "http://xxx.xx.xx.xxx:xxxx"
$Item.ItemName = "xxx/xxx/xxx"
$ItemList.Items = $Item
$Proxy.Read($Options, $ItemList, [ref]$RItemList, [ref]$Errors)
#Show result
$rTimeStamp = $RItemList.Items[0].Timestamp.ToString('yyyy-MM-dd HH:mm:ss')
$rItemName = $RItemList.Items[0].ItemName
$rValue = $RItemList.Items[0].Value
Write-Host ("{0}: {1}={2}" -f $rTimeStamp, $rItemName, $rValue)
In my result above I see the following in $RItemList.Items[0]
DiagnosticInfo:$null
Value: [UInt32[32]]
Quality: [OPCQuality]
ValueTypeQualifier: $null
ItemPath: ""
ItemName: "xxx/xxx/xxx"
ClientItemHandle: $null
Timestamp: 2020-12 19 01:00:00
TimestampSpecified: $true
ResultID: $null
and when I dive deeper into Value above I see that it is read as expected. So far so good...
Now to my problem; I cannot understand how to write to this same Item via another script.
This is my attempt
$wsdl=(Join-path $PSScriptRoot "OpcXmlDa1.00.wsdl")
$Global:Proxy = New-WebserviceProxy $wsdl –Namespace X
$Global:Options = New-Object X.RequestOptions
$Options.ReturnItemName = $true;
$Options.ReturnItemTime = $true;
$Options.ReturnDiagnosticInfo = $true;
$Global:writeItemList = New-Object X.WriteRequestItemList
$Global:RItemList = New-Object X.ReplyItemList
$Global:Errors = New-Object X.OPCError
$Global:ItemSessionRequest = New-Object X.ItemValue
$ItemSessionRequest.ValueTypeQualifier = 'xsd:unsignedInt' #<- I believe that this might be the issue?
$ItemSessionRequest.ItemPath = ""
$ItemSessionRequest.ItemName = "xxx/xxx/xxx"
$ItemSessionRequest.Value = #($x;$y;$z) #<- I have what I want to write in $x, $y, $z
# Write to OPC server
$Proxy.Url = "http://xxx.xx.xx.xxx:xxxx"
$ReturnValuesOnReply = $true
$writeItemList.Items = $ItemSessionRequest
$Proxy.Write($Options, $writeItemList, $ReturnValuesOnReply, [ref]$RItemList, [ref]$Errors)
I get two errors (I'm running via VSC-code).
Error #1:
DiagnosticInfo : This value to write cannot be NULL
Value :
Quality :
ValueTypeQualifier :
ItemPath :
ItemName : xxx/xxx/SessionRequest
ClientItemHandle :
Timestamp : 1970-01-01 00:59:59
TimestampSpecified : True
ResultID : http://opcfoundation.org/webservices/XMLDA/1.0/:E_BADTYPE
I've assumed that this has to do with my choice of $ItemSessionRequest.ValueTypeQualifier (where I've tried a lot of alternatives).
Error #2: This error comes if I run the script a second time in the same instance
Cannot convert argument "Options", with value: "X.RequestOptions", for "Write" to type "X.RequestOptions": "Cannot convert the "X.RequestOptions" value of type "X.RequestOptions" to type "X.Request
Options"."
At C:\bla.bla.ps1:79 char:1
+ $Proxy.Write($Options, $writeItemList, $ReturnValuesOnReply, [ref]$RI ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodException
+ FullyQualifiedErrorId : MethodArgumentConversionInvalidCastArgument
I guess this has something to do with the $Proxy variable
I'm grateful for help and I apologize if I missed something relevant, but I have done my best...

Answer 1

In this case problem no 1 was solved by the following
$ItemSessionRequest.Value = #($x;$y;$z)
A work around for problem no 2 was by using a new session inside the script, see 1