DS-6610B-L can be forced to work at 2GB of speed

I want to know if we can force  a port (will be configured for ISL) to work at 2GB of speed on Connectrix DS-6610B-L or the supported speeds are only 4, 8, 16 or 32 Gb/s? If not supported. If it is possible to force it to work at 2GB, this will be by using which SFP model? 

I checked the official document (https://www.delltechnologies.com/asset/en-us/products/storage/technical-support/h16567-connectrix-ds-6600b-switches-ss.pdf).

It mentions that:

-DS-6610B-L can work at 4, 8, 16 or 32 Gb/s speeds depending on the installed optic.

-32Gb/s SFPs can operate at 32, 16 or 8Gb/s; 16Gb/s SFPs will operate at 16, 8 and 4Gb/s.