Fast Onboard Inputs And Outputs; Target System Memory; Type Of Memory - Siemens SINUMERIK 828D Function Manual

14.3.1.4

Fast onboard inputs and outputs

SINUMERIK 828D provides 4 inputs and 4 outputs "onboard". These are also fed to the outside at connector
X142; therefore no I/O modules are required and these I/O can be especially quickly processed ("fast I/O").
As standard, these IO are assigned to the NCK, the assignment to the PLC is described in:
References:
Commissioning Manual SINUMERIK 828D
Addressing the onboard inputs:
Addressing the onboard outputs:
The onboard IO is not assigned to an image memory; reading and writing are always directly made to/from the
hardware. This is the reason that direct operation commands must be used when accessing this IO:
• Direct NO contact
• Direct NC contact
• Directly set bit value
• Directly reset bit value
• Directly assign bit value
It makes sense to use the interrupt program INT0 for this purpose, because these command can be executed as
quickly as possible in the servo cycle.
14.3.2

Target system memory

14.3.2.1

Type of memory

Type Description
I Digital inputs and process
image input
Q Digital outputs and
process image output
M Internal bit memory
SM Special bit memory
(SM0.0 - SM0.6 are write-
protected)
V Variable memory
T Actual values of timers
and time bits
C Actual values of the
counters and count bits
AC Accumulators
L Local data memory
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
I256.0 ... I256.3
Q256.0 ... Q256.3
Access in the Access in the
bit format type format
read / write read / write
read / write read / write
read / write read / write
read / write read / write
read / write read / write
Time bit no
read / write
Counter bit no
read / write
no read / write
read / write read / write
P4: PLC for SINUMERIK 828D
-| I |-
-| /I |-
-(SI)-
-(RI)-
-( I )-
Access in the
Access in the
double word
word format
format
read / write read / write
read / write read / write
read / write read / write
read / write read / write
read / write read / write
actual value of no
time
read / write
actual value of no
the counter
read / write
read / write read / write
read / write read / write
14.3 Programming
can be
retentive
no
no
no
no
yes
no
no
no
no
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