Flying an IAN approach with 737NGX, (Integrated Approach Navigation) the scale ID annunciation indicates FMS.
The Scale ID should be FMC not FMS.
The possible scale ID annunciations are in FCOM 10.11.14 and there is not such an indication(FMS).
The manual says: FMC - (IAN approach)
Also here is a picture from Boeing:
http://www.boeing.com/commercial/aeromagazine/aero_22/approach_fig3.html
It is only a typical error in the implementation of 737ngx, (If I am right) which does not affect the operation of the aircraft but it would be nice to be corrected some time.
I would appreciate a comment especially from PMDG support.
Thank you for your attention.
Emmanuel Argiropoulos
LGMT