Set AnhorId for Managed Metadata Fields to Taxonomy Term GUID

Set AnhorId for Managed Metadata Fields to Taxonomy Term GUID.ps1

$siteColl = Get-SPSite -Identity "http://sp2013/sites/EDMS"
$spSite = [Microsoft.SharePoint.SPSite] ($siteColl)
$TaxSession = Get-SPTaxonomySession -Site $SiteCollection
$TermStore = $TaxSession.TermStores[“Managed Metadata Service”] #Change to your service name
$TermStore.Id
#Get the Term Set
$TermStoreGroup = $TermStore.Groups[“Functions”] #Change to your Terms Store group name -the main parent term
$TermSetList = $TermStoreGroup.TermSets
#create an array
$myArray = $TermSetList.Terms

if($spSite -ne $null)
{
   foreach($subWeb in $spSite.AllWebs)
   {
      if($subWeb -ne $null)
      {         
         Write-Host "Subsite : "  $subWeb.Name + " - " + $subWeb.Url
         $spListColl = $subweb.Lists
         foreach($list in $spListColl)
         {
            if($list.Title -eq "Documents") #Rename to your doc library
            {
			write-host $list.Title -ForegroundColor Red			
			foreach ($field in $list.Fields) #Get all fields the library
                { 
                    if($field.staticName -eq "DocumentFunction") #Rename to your Managed Metadata field
                    {   
                        #Write-Host $fielD " | " $field.schemaxml -ForegroundColor Green #Uncomment if you want to see the schema for the field  
                        #Write-Host $field.AnchorId -ForegroundColor green #Uncomment if you want to see the existing AnchorId
                        foreach ($element in $myArray)
                        {
                            if ($subweb.Title -eq $element.name) #finds the term that matches the sitename
                            {
                            Write-Host $subweb.Title " will be updated" -ForegroundColor green 
                                $field.AnchorId = $element.id  #elementid is the guid of the term - set this as the AnchorId
                                $field.Update()
                            }
                        }                                              
                    } 
                }  
            }
         }
         $subWeb.Dispose()
      }
      else
      {
         Echo $subWeb "does not exist"
      }
   }
   $spSite.Dispose()
}
else
{
   Echo $siteURL "does not exist, check the site collection url"
}
Echo Finish