The administrative status of CSM modem diag table. The value
'enabled' enables csmLanModemDiagTable and 'disabled' stops
csmLanModemDiagTable from continuing collecting diagnostic
information. GenError is returned when trying to enable
this object if no JDEC card present. This object can also
be set via parameter 'cms-modem-diag' in TNT snmp profile.