VM600 MPS hardware manual (standard version) MAMPS-HW/E 3 - 7
Edition 17 - February 2018
VM600 6U 19" rack backplane (ABE04x)
GENERAL SYSTEM DESCRIPTION
The P1 bus, on the front side of the backplane, is used for slots 0 to 14 in order to implement
a standard VME bus on the front side of the backplane. This corresponds to the VME 16
specifications and allows 24-bit address and 16-bit data transfers between cards in the rack.
NOTE: The safety version of the MPC4 card (MPC4SIL) does not have a VME bus
interface so it cannot communicate with a CPUM or any other cards in a VM600
rack (see 4 MPC4 / IOC4T card pair).
The P2 and P4 connectors are used for slots 0 to 14 in order to connect the card in the front
card cage to the card immediately behind it in the rear card cage (through connections).
Slots 15 and 18 of the rack are reserved for RPS6U rack power supplies. The backplane is
equipped with special high-current connectors (type H15) for these power supplies.
The P3 bus, on the rear side of the backplane, actually consists of the following three buses:
1- The Tacho Bus
This is composed of eight lines. These lines have passive terminations.
The Tacho Bus is common to all slots in the rack. It is intended for the transfer of speed
and phase reference signals between cards.
See 3.4.2 Tacho Bus for further information.
2- The Open Collector (OC) Bus
This is composed of 96 open collector (“ground/open") lines. These lines do not have
terminations.
The OC Bus is sub-divided into 6 buses each having 16 lines (these buses are called
OCA, OCB, OCC, OCD, OCE, OCF). Each of these six buses is associated with three
slots (with each slot associated with only one bus).
See 3.4.3 Open Collector Bus for further information.
3- The Raw Bus
This is composed of 32 x 2 lines. These lines do not have terminations.
The Raw Bus is common to all slots in the rack.
See 3.4.4 Raw Bus for further information.
The Tacho Bus, the Open Collector Bus and the Raw Bus are not buses in the
microcomputing sense of the term, that is, there is no protocol, handshaking, timing and so
on. Rather, they should be thought of as groups of lines that can be used to transmit signals.
NOTE: See Appendix C - Definition of backplane connector pins for full details on the P1,
P2, P3 and P4 connectors.
See also 8.2 Attribution of slots in the rack for further information on which VM600 cards can
be installed in which slots of a VM600 rack (ABE04x and ABE056).