Data That Are Cyclically Exchanged; Alarms And Messages - Siemens SINUMERIK 840D sl Function Manual

14.1.2.1

Data that are cyclically exchanged

Data which is exchanged between the PLC and NC on one side as well as between the PLC
and HMI on the other side.
Data to the PLC are provided by the firmware at the cyclic start of the user program. This
ensures, for example, that the signals from the NCK remain constant throughout a cycle.
The firmware transfers data from the PLC to the NKC or HMI at the cycle end of the user
program.
Interface PLC ↔ NCK
The cyclic data include, e.g. status signals ("program running", "program interrupted") and
control signals (start, stop) and auxiliary and G functions.
Data are structured in signals for:
● Modes
● Channels
● Axes/spindles
● General NCK signals
Interface PLC ↔ HMI
These are signals for:
● Program selection via lists
● Messenger control command
● General signals from/to HMI
● Signals from/to the maintenance planner
● Signals from operator panel (retentive area)
● General selection/status signals from/to HMI (retentive area)
14.1.2.2

Alarms and messages

The user interface in DB1600 offers the option of displaying fault and operating messages on
the HMI.
The firmware evaluates the signals that have been entered and sends these as coming and
going alarms and messages to the HMI where they are displayed. The HMI manages the fault
texts.
Note
A maximum of eight PLC alarms is displayed on the HMI.
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
P4: PLC for SINUMERIK 828D
14.1 Overview
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