The invention provides a thermal uniformity compensating method and apparatus. A combination of instances of one or more function block types is capable of implementing a control process in a controller within a process control system. The activation system has a switch, a wireless communication device, and a communication cord. The latching member is slidably attached to the base body. In accordance with the invention, the locking means are declutchable, so as to enable the end-piece to be dismounted from the front end of the spine member.