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21 Terms and Abbreviations
MPC
Abbreviation for multipoint controller, interface to a serial
(MPC) bus. Used in the SINUMERIK 880, for instance, to
connect the operator panel to the COM CPU and for
linking EUs to the central controller.
MPF
Abbreviation for main program file, designates a memory
area in the NC for part programs
Multiport RAM
A type of memory module with the link RAM
NC
Numerical control. Often used in this publication to refer
to the NC area (or the NC CPU) of the SINUMERIK 880
(see Section 1, General Overview).
NC channel
The NC area of the SINUMERIK 880 comprises NC
channels. The principal components of each NC channel
are a block preparation function for part programs,
an interpolator and an interface to the PLC
NC part program
Part program
Normal mode
Mode of the PLC CPU in which the PLC program can
be interrupted only at block limits. For this reason
hardware interrupts, for example, cannot be processed in
the normal mode (see "PLC 135 WB Planning Guide",
own documentation)
OB
Abbreviation for organization block
Operator panel I/Os
Machine signals connected to the operator panel by
I/O submodules (see Section 1)
Option
Supplement to the standard functionality of the
SINUMERIK 880
Overall reset
Reset of all editable memory areas, combined with the
entry of fixed initial values where applicable (also "general
reset")
Part program
Program for the numerical control, for machining the
workpiece with the controlled machine
PB
Abbreviation for program block
PCB
Module for installation in the central controller or in an
expansion unit
Peripheral byte
A byte of the I/O address area. The I/O address area
accommodates the input and output signals; also see
PII, PIQ
Peripheral word
A word (two consecutive bytes, starting with an even
address) in the I/O area; see peripheral byte
PII
Abbreviation for process input image (see Section 1)
© Siemens AG 1991 All Rights Reserved 6ZB5 410-0HE02
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SINUMERIK 880 (PJ)