The firmware of all FEEs was updated to the version in FEE_GF_Feb16_16.bin (https://elog.ph.ed.ac.uk/AIDA/215).
This provides a 25 MHz clock output from MACB, plus a manual reset request signal.

Attached are screen captures from smooth updating procedure. 

Checked correlation request signal from output2 of MACB: it's a pulse with ~180ns width and -0.7V. We could only
observe it when selecting 'act no all FEEs' in Correlation Control browser window (looking at MACB module on the
top of the tree). However, we didn't check that the output is produced from only one MACB module, if we select
the one of the corresponding FEE.