Devices in a process control system communicate by data messages over a
communication medium segment. Each device includes a communication
controller that includes a received data memory and a plurality of
received message objects. When a message is received, a received message
object is activated, and the initial position of a write pointer in the
received data memory is stored in the received message object. During
message reception, if a hardware device determines that the message is to
be ignored, the received message object is deactivated, thereby
preventing further writing of the message to the received data memory.
The write pointer is then preferably returned to its initial position as
stored in the received message object.