This read-only CienaGlobalState object reports the actual operational state of a PM instance, per its description, reflecting whether the instance is truly collecting data right now, as distinct from cienaCesPmInstanceAdminState which reflects only the administratively requested state. An instance can be administratively enabled yet operationally disabled, for example if the global cienaCesPmGlobalState is off, or the monitored interface itself is down, so this field is what actually confirms data is being collected. An engineer confused about why an administratively-enabled PM instance shows no new data would check this operational state to see whether some other condition, global PM state or interface down, is preventing it from actually running.