Read Only

Parameter Read Only defines the initial Read Only State for data read from the field device for Tags and BLOCK:PARAMETERS created using this parameter. Specifies that the Tag or BLOCK:PARAMETER value is read only.  If READ ONLY is selected, users and operators cannot change the value of the Tag or BLOCK:PARAMETER in run-time VIEW. Only the field device can update the value of the tag.  Other Tag fields are changeable.

If you want to allow some users to change the value of the tag, but not all users, assign a security Area and Level to the tag or BLOCK:PARAMETER.