1 General on the SINUMERIK 840Di
1.1 Overview of SINUMERIK 840Di
1. Data consistency after a loss of voltage can only be ensured if the power
supply of the PCU is at least 24V.
2. In the remaining time left by the internal power backup, Windows NT can no
longer be ended correctly. This implies the risk that the Windows NT instal-
lation can be damaged so that the SINUMERIK 840Di can no longer be run.
It is therefore urgently recommended to use an uninterruptible power sys-
tem (UPS) (see Subsection 1.1.8, page 1-29).
3. If the MCI board or its battery is replaced after a loss of voltage, this will
result in a data loss of the user data battery-backed on the SRAM of the
MCI board. How to proceed further: see Subsection 6.3.4, page 6-183.
With the SINUMERIK 840Di, three different temperatures are monitored for
reaching their appropriate threshold values:
1. Housing temperature
2. CPU module temperature
3. CPU temperature.
Alarm: "2110 NCK temperature alarm"
Logbook entry: "Alarm: Critical temperature values: Case
When a temperature alarm is issued, the temperature measured for the fol-
lowing components is displayed in the logbook entry: case, CPU module
One of the three monitored temperatures has reached or exceeded its threshold
value. The temperature must be reduced below the threshold value by at least
7°C before the alarm is reset.
If the temperature alarm occurs, the user and/or the machine manufacturer
(PLC program) must decide whether he interrupts the machining and quits or
turns off the SINUMERIK 840Di.
To guarantee safe operation of the SINUMERIK 840Di, WINDOWS NT must be
shut down correctly before the PCU is switched off.
Windows NT is shut down correctly as follows:
– Windows NT start bar: Start > Shutdown
– PLC interface signal: "PC shutdown", see Subsection 16.1.1,
Siemens AG, 2003. All rights reserved
SINUMERIK 840Di Manual (HBI) – 06.03 Edition