Python Code for Setting Obtained from Tool property

Is is possible to set the Obtained from property for a parameter in Validation using python code?

I have populated a string parameter with a list of tables selected in Table View parameters. If the user selects a table name in the string parameter I would like to populate a Field data type parameter with the list of fields for the selected table.

def updateParameters(self):
"""Modify the values and properties of parameters before internal
validation is performed. This method is called whenever a parmater
has been changed."""

if self.params[0].altered:
tblList = [""]
desc = arcpy.Describe(self.params[0].value)
tblList.append(desc.name)
if self.params[1].value:
desc = arcpy.Describe(self.params[1].value)
tblList.append(desc.name)
if self.params[2].value:
desc = arcpy.Describe(self.params[2].value)
tblList.append(desc.name)
self.params[6].filter.list = tblList
self.params[8].filter.list = tblList
self.params[10].filter.list = tblList
if self.params[1].altered:
tblList = [""]
if self.params[0].value:
desc = arcpy.Describe(self.params[0].value)
tblList.append(desc.name)
desc = arcpy.Describe(self.params[1].value)
tblList.append(desc.name)
if self.params[2].value:
desc = arcpy.Describe(self.params[2].value)
tblList.append(desc.name)
self.params[6].filter.list = tblList
self.params[8].filter.list = tblList
self.params[10].filter.list = tblList
if self.params[2].altered:
tblList = [""]
if self.params[0].value:
desc = arcpy.Describe(self.params[0].value)
tblList.append(desc.name)
if self.params[1].value:
desc = arcpy.Describe(self.params[1].value)
tblList.append(desc.name)
desc = arcpy.Describe(self.params[2].value)
tblList.append(desc.name)
self.params[6].filter.list = tblList
self.params[8].filter.list = tblList
self.params[10].filter.list = tblList

if self.params[6].altered:
At this point I would like to populate self.params[7] with a list of fields corresponding to the table selected in
self.params[6]

self.params[7] is currently a Field data type