Patent ID: 8718894

Claim:
A communication system having at least a first and a second communication unit, wherein the first communication unit has a counter memory unit which stores a counter value (MSG_CNT), wherein the first communication unit is configured such that at least an occurrence of a first defined communication event prompts the counter value in the counter memory unit to be changed in at least one defined first manner, wherein at least an occurrence of a defined reference event is followed by the counter value in the counter memory unit is changed in at least one defined second manner, wherein at least in the course of a second defined communication event the first communication unit transmits the current counter value in the counter memory unit directly or indirectly to the second communication unit, wherein the first communication unit has at least one first and a second data memory unit (MemA, MemB) and is configured such that at least the occurrence of the first defined communication event prompts a current data item in the first data memory unit (MemA) to be written to the second data memory unit (MemB) and prompts the counter value (MSG_CNT) in the counter memory unit to be changed in the defined first manner.