1 General Overview
01.93
1.4.3 Interrupt-generating I/O devices
Interrupt-generating signals at the EU-MPC
c)
Besides the EU link, the EU-MPC interface module contains 8 interrupt inputs. Signal changes
at these inputs trigger a group interrupt at the PLC accommodating the local bus to which the
EU-MPC is connected. Up to 3 EU-MPC modules can be inserted per PLC.
The interrupt inputs on the EU-MPC are equipped with interference suppression filters with a
running time of approx. 2 ms.
Interrupt-generating signals at DMP submodules
One interrupt byte per DMP interface (interface DMP) module can be defined by means of
machine data. The interrupt byte is always the first input byte of a DMP submodule. The DMP
firmware periodically evaluates the interrupt byte and generates a group interrupt at the PLC in
the event of a relevant signal change (correct edge, signal not masked). Up to 3 DMP
interfaces (interface DMP) can be connected per PLC.
The following applies to GA2 with free configuration:
Up to four interrupt bytes are assigned to the DMP modules in the configuration DB. More than
one interrupt byte can assigned to one DMP module.
The interrupt inputs on the interface DMP are equipped with interference suppression filters
with a running time of approx. 0.5 ms. Despite the serial mode of data transfer, the reaction
time is equivalent to that achieved with interrupts by the EU-MPC.
Interrupt processing
The group interrupt generated by an EU-MPC or DMP interface activates an interrupt routine
of the PLC operating system. This routine makes all the required basic signals available in the
flag area and calls OB 2 of the PLC user program. In OB 2 the PLC user program can identify
which signal triggered the interrupt with reference to an image of the interrupt byte in the basic
signals and is thus able to react accordingly.
Principle of interrupt-generating I/O devices with EU-MPC
PLC start
Interrupt processing
Interrupt routine
a a a a a a
a a a a a a
a a a a a a
a a a a a a
a a a a a a
OB 2
a a a a a a
a a a a a a
a a a a a a
a a a a a a
OB 1
a a a a a a a a a a a
a a a a a a a a a a a
a a a a a a a a a a a
a a a a a a a a a a a
PLC MD
a a a a a a a
a a a a a a a
a a a a a a a
a a a a a a a
a a a a a a a
Flags
a a a a a a a a a
a a a a a a a a a
a a a a a a a a a
a a a a a a a a a
EU-MPC
Input circuit optocoupler
filter time 2 ms
Interrupt controller
Edge evaluation
a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a
. . . . . . . . . . . .
a a a a a a a a a
a a a a a a a a a
a a a a a a a a a
a a a a a a a a a
a a a a a a a a a
. . . . . . .
a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a
8 interrupt inputs
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
a a a a a a a a a a a a
Interrupt
image
a a a a a a a a a a a a a
a a a a a a a a a a a a a
a a a a a a a a a a a a a
a a a a a a a a a a a a a
a a a a a a a a a a a a a
a a a a a a a a a a a a a
a a a a a a a a a a a a a
a a a a a a a a a a a a a
a a a a a a a a a a a a a
a a a a a a a a a a a a a
Initial ad-
dress
Mask
Edge
_______
c)
up to and including software version 6
1–38
© Siemens AG 1991 All Rights Reserved 6ZB5 410-0HE02
SINUMERIK 880 (PJ)