8960 trigger out

I measured a moble phone test item "ORFS in receiver band"
One of the setup that I don't understand.

I connected 8960 "Trigger out" to spectrum analyzer "Gate Trigger Input".
And set it as trigger slot=7 & gate trigger>200 bursts
Could anyone tell me what's this connection & setup for?
Thanks.

The modulation spectrum is done in Gated Mode. It will be measured only the bits that are in the middle of the burst (from 87 to 132). To do this test the Spectrum Analyzer shall be triggered. Check the spec ETSI 11.10 paragraph 13.4.4.2
Not all the Spectrum Analyzers allow doing a Gated Trigger test (you have to set up a window in the middle of the burst).