The value of tmnxChassisAdminMode specifies the scaling and feature
set for all of the IOM cards in the chassis.  Setting
tmnxChassisAdminMode to a particular mode corresponds to the scaling
and feature sets supported on that IOM card type. The following table
describes the maximum mode capable per IOM (ie. 'modeC' scaling and
feature sets cannot be supported on either the iom-20g or the
iom-20g-b):

     IOM                MODE (maximum)
     ----------------   --------------
       iom-20g            modeA
       iom-20g-b          modeB
       iom2-20g           modeC
       iom3-xp/imm        modeD

An attempt to change the value of tmnxChassisAdminMode from a lesser
mode to a greater mode (ie. Upgrading from 'modeA' to 'modeB') without
also setting tmnxChassisModeForce to a value of 'doAction' in the same
SNMP SET request, will fail with an inconsistentValue error if there
are any IOM cards in the chassis with a tmnxCardAssignedType value that
does not support the new mode.

Changing the value of tmnxChassisAdminMode from a greater mode to a
lesser mode (ie. Downgrading from 'modeC' to 'modeA') will not take
effect until after saving the configuration and rebooting the system.