WHERE clause using OPENQUERY with linked server

I connect with MS SQL Server Express 2012 a Database via ODBC.

My query:

Select * from openquery(test,'SELECT * FROM Versuchsanlage_DB WHERE value =27')

SQL QUERY

But this query

 Select * from openquery(test,
   'SELECT * FROM Versuchsanlage_DB 
    WHERE identifier = AGENT.OBJECTS.Versuchsanlage.Variable_1_Byte')

Select * from openquery(test,
   'SELECT * FROM Versuchsanlage_DB
    WHERE identifier = Variable_1_Byte')

doesn't work. Why?