The M7310 Busy Lamp Field (BLF) module is a great tool. However, Nortel M7310 users need to be aware that the BLF module doesn't work on all generations of ICS software.
The BLF module only works on KSU software versions 6.0 and LOWER. It will NOT work on versions 6.1 or 7.0.
This problem is also evident on older M7310 phones (1st generation), where adjusting the contrast on the BLF will only show 4 levels of adjustment versus the NINE levels of adjustment that are available on newer phones.
If your Nortel ICS phone system uses software revision 6.1 or 7.0, you'll need a T7316 phone and a KIM CAP module instead of the M7310 and a BLF module.
Thought you'd all like to know.