Siemens SINUMERIK 840D sl Manual page 143

Note
The "alive and well" counter is a 3 bit modulo counter at the PP application level. The PP
application can be monitored using this counter. Failure of the application software does not
generally result in a communication failure, as this is developed in a hardware-supported
manner. The watch dog switches off the digital outputs, while the inputs remain at their last
set values.
Table 9-67
"alive and
well" counter
0
1
2
3 ... 7
Table 9-68 Elimination of error for "alive and well" counter status "2"
Value Cause
byte 1
1 In the temperature
measurement operating
mode, an input voltage is too
high. The hardware may
become damaged/
destroyed as a result.
2 Reserved
3 Overload at the outputs
4 Incorrect operating mode
selection, e.g. temperature
measurement at the analog
outputs.
5 Internal error, system error
NCU 7x0.3 PN, NCU 7x0.3B PN
Manual, 06/2014, 6FC5397-1EP40-5BA1
Overview of the messages in byte 1, depending on the "alive and well" counter
Value Message
byte 1
0 Reserved
Temperature value
0 No error
1 Impermissible input voltage in the temperature measurement mode
2 Reserved
3 Overload at the outputs
4 Incorrect operating mode selection
5 Internal error, system error
6 Range exceeded at the inputs
7 Range exceeded at the outputs
0 Reserved
Effect
The "PNFault" LED is activated.
The outputs are disabled.
The value 0x80 is stored in status byte 1.
-
The "PNFault" LED is activated.
The outputs are disabled.
The value 0x80 is stored in status byte 1.
Selection of operating mode is rejected,
The "PNFault" LED is activated.
The outputs are disabled.
The value 0x80 is stored in status byte 1.
Remedy
It is essential that a Pt100 element is
connected to terminals 3.4 or 7.8.
1)
The module must be restarted with
Power ON after the error has been
eliminated.
-
Check the loads at the analog output.
The module must be restarted with
1)
Power ON after the error has been
eliminated.
If selected correctly, the module switches
to cyclic operation.
The firmware has detected a system
error, this status can only be exited by
1)
means of a switch-on / switch-off.
Connectable components
9.3 PP 72/48D 2/2A PN
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