ABB AC 800M, Manual

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Section 1 Introduction PM8xx/TP830 Processor Unit – General
3BSE036351-510 A 33
PM8xx/TP830 Processor Unit – General
Physically the PM8xx/TP830 Processor Unit consists of two basic parts:
• Processor Unit
(PM851/PM851A/PM856/PM856A/PM860/PM860A/PM861/PM861A/

PM864/PM864A/PM865/PM866) with processor and Power Supply boards.
• Baseplate (TP830), housing the unit termination board.
For the Functional Block Diagram, see Figure 4 on page 35 and

Figure 5 on page 36. The CPU board contains the microprocessor and the RAM-
memory, controllers for all built-in communication interfaces, real-time clock, LED
indicators, INIT push button and a Compact Flash interface.
The main function of the power supply board is to generate isolated, circuit-proof
+5 V and +3.3 V supplies to the CPU and I/O units. The board also contains opto-
isolated RS-232C drivers/receivers for the service port, together with a back-up
battery holder for memory/real time clock, (RTC).
The termination board, housed in the TP830 Baseplate, is where the majority of
the external connections terminates. The board is grounded to the DIN-rail through
of the metallic components of the housing. The termination board is provided with
screw terminals for power supply and redundant power supply monitoring, with
RJ45 connectors for the control network and serial port, a connector for the service
port, the electrical ModuleBus and the CEX-Bus.
The 24 V DC supply, connected to the TP830 Baseplate, powers all the units on the
CEX-Bus and the electrical ModuleBus.
In single CPU configuration, it is possible to connect an S800 I/O cluster directly to
the built-in electrical ModuleBus plug located on the right hand side of the TP830
Baseplate.
The processor unit has a communication expansion bus connector located on
the left-hand side of the TP830 Baseplate. This CEX-Bus provides for extending
the on-board communication ports with additional communication interfaces.
The topic does not apply to PM891. See PM891 Processor Unit – General on
page 40.