If this attribute is set to a value of 'true' the CM must begin looking for the presence of the Trigger Message Block in the PLC with a Group ID matching the CM's 'docsPnmCmDsOfdmSymTrigGroupId'. The TrigEnable is a one-shot enable and the attribute is internally disabled when a PLC containing a Group ID matching the CM's 'docsPnmCmDsOfdmSymTrigGroupId' in a Trigger Message Block is received. If this attribute is set to a value of 'false' the CM must stop looking for the presence of the Trigger Message Block in the PLC with a Group ID matching the CM's 'docsPnmCmDsOfdmSymTrigGroupId'. In this case the value of the 'docsPnmCmDsOfdmSymMeasStatus' attribute will be set to 'inactive'. When read, the CM must return a value of 'true' if the CM is actively looking for the presence of the Trigger Message Block in the PLC with a Group ID matching the CM's 'docsPnmCmDsOfdmSymTrigGroupId'. Otherwise the CM must return 'false'. Interaction with other table rows: - This object is subject to the rules specified by the 'docsPnmCmCtlStatus' object. Therefore this object returns 'inconsistentValue' if set to 'true' while the value of 'docsPnmCmCtlStatus' is any value other than 'ready'. - This object returns 'inconsistentValue' if set to 'true' while the CM is in DOCSIS Light Sleep (DLS) mode or the CM is in battery-backup mode. - Default values for 'docsPnmCmDsOfdmSymCaptFileName', 'docsPnmCmDsOfdmSymTrigEnableTimeout', and 'docsPnmCmDsOfdmSymTrigGroupId' objects are defined; thus, this object may be set to 'true' without explicitly setting these values. Care should be taken to insure these values are correct for the desired test case. - Setting this attribute to a value of 'true' will change the value of the 'docsPnmCmDsOfdmSymMeasStatus' attribute to 'busy'.