[Premium-Rx] Rohde Schwarz, ESMC - info wanted

[vk3xyz]

Hi,
Given R&S has come up in the last couple of digests, I have a couple of
queries.

Would anyone have any information on the ESMC "Operating Unit" connector on
the front panel of the remote versions? I'm after the pinout and if it's
serial, which I assume it is, the protocol and messages?

Haven't been able to locate much on this RX. I have the user manual but
there is no reference to the remote version. It does discuss serial control
and gpib control, but I specifically want info on the front panel connector
which would connect, I expect, to the ESMC-GB control panel , my RX has a 37
pin D type.

The esmc-gb looks something like this 
https://www.bidspotter.co.uk/en-gb/auction-catalogues/ramco/catalogue-id-ram
co-10106/lot-c4ae72b6-fc51-45dd-9a69-a90000a35287

or per page 5 of the datasheet
http://pdf.textfiles.com/manuals/SCANNERS-F-R/Rohde&Schwarz_ESMC%20HF%20reci
ever_Datasheet.pdf

thanks in advance
Greg
(Apologies if this gets posted twice - I think the 1st was culled due to an
embedded pic of the esmc-gb)