Siemens SINUMERIK 880 SW 6 Planning Manual page 51

01.93
Assignment of I/O modules to a PLC
The I/O devices are divided into I/O device groups. Each I/O device group comprises 64 sign-
als, equivalent to 8 peripheral bytes. Up to 20 I/O device groups for inputs and 20 I/O device
groups for outputs accordingly exist for the maximum complement of 1280 inputs and 1280
outputs.
The PLC machine data contain assignment tables for assigning an I/O device group to a PLC.
The assignment tables indicate whether an I/O device group is to be processed by its own
PLC and whether local access is available to the I/O device group of PLC I or PLC II.
Assignment of I/O device groups:
PLC I
Inputs: MD 6400...MD 6419
Outputs: MD 6480...MD 6499
The outputs can be processed (in groups in each case) only by one PLC.
Note:
• Only local access is available to signals connected via DMP submodules. (Also see
"Local I/O devices" Section.)
• Also refer to the "Global I/O devices" Subsection in the "Operation with two PLCs"
Section if appropriate.
1.4.3 Interrupt-generating I/O devices
The SINUMERIK 880 offers two ways of initiating program interrupts owing to I/O device signal
changes.
A program interrupt can be triggered by
• Edge changes in alarm bytes or
• Hardware interrupts.
Program interrupts owing to edge changes in alarm bytes are described in the "Reaction to
interrupt and alarm signals" Section.
Periodic evaluation of alarm bytes is too slow for some applications. Besides the alarm signals
each PLC can process up to 24 or 32
The interrupt-generating signals can be connected to the EU-MPC EU interface module
DMP submodules. They can be individually masked or enabled by PLC machine data or by
"free configation"; the interrupt-generating edge (rising or falling) can also be specified
separately for each signal.
_______
1) If using a SIMATIC S5-155U, refer to SINUMERIK 880 with S5-155U, Difference Description to PLC 135 WB in
this context
c) up to and including software version 6
d) with GA2, software version 1 and higher with free configuration
© Siemens AG 1991 All Rights Reserved
SINUMERIK 880 (PJ)
c)
PLC II
MD 6420...MD 6439
MD 6500...MD 6519
1)
d)
interrupt-generating signals in 3 or 4
6ZB5 410-0HE02
1 General Overview
1.4.2 Distributed I/O devices
d)
interrupt bytes.
c)
or to
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