Hello, why do you need "backplane diagrams" of Aruba 5400R zl2 and HP ProCurve 5400 zl Switch Series?
And...what do you exactly mean with "backplane diagrams" with regard to of Aruba 5400R zl2 and HP ProCurve 5400 zl Switch Series?
Both series have a modular design: that is, apart from the pre-installed Management Module, both series provides 6 or 12 open slots chassis (respectively on 5406 and 5412 models) named A, B, C, D, E and F for the 6 slots model and A, B, C, D, E, F, G, H, I, J, K and L for the 12 slots model.
Open slots should be equipped with various Modules types (refer to each Switch updated QuickSpecs to see the full list of supported modules); those modules - once installed on free chassis's slots - communicate through the internal backplane with the Management Module.
You can't connect "directly" to the backplane because the backplane is internal, only frontplane connections (AKA Modules' ports) are admitted.
QuickSpecs, Datasheet and Management and Configuration Guides will explain/show you in detail what I wrote above.
Said so, if you have an uplink (made of one or more physical links)...it should be terminated into the relevant Module's port or distributed to ports that belongs to different Modules (for redudancy) if that is required by your implementation.