Compatibility KTN-STL4 to CX300

Hello,

I have a CX300 and I would like to add an extension disks model EMC KTN-STL4.

I pluged them with a cable HSSDC-HSSDC2.

My controller is on the CX300 and the led on the port BE0 from CX300 is off and the same thing on port Primary (HSSDC2) on KTN-STL4.

So from my CX300 i can't see my disks which are the KTN-STL4.

Maybe upgrade flare on CX300 ?

Anyone help ?

Thanks