Bit mask representing the status of the LEDs on the module.
Each LED is represented by 2 bits. LED #33 status is
indicated by the 2 least significant bits. LED #48 status
is indicated by the 2 most significant bits. How this bit
mask is interpreted depends on the module ID. For example,
some modules use this value to report what color the LED
is currently set to ('00' off, '01' yellow, '10' green).
This value can be used by a NMS that needs to know this
information for whatever reason. Some modules may not
support this value in which case it should be set to zero.