Siemens SINUMERIK ONE NCU 1740 Equipment Manual page 154

Connectable components
12.3 PP 72/48D PN 2/2A PN
Bit
2
1
0
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 12-64
"alive and
well" counter
0
1
2
3 ... 7
Table 12-65 Elimination of error for "alive and well" counter status "2"
Value Cause
byte 1
1 In the temperature measure‐
ment operating mode, an in‐
put voltage is too high. The
hardware may become dam‐
aged/destroyed as a result.
2 Reserved
3 Overload at the outputs
4 Incorrect operating mode se‐
lection, e.g. temperature
measurement at the analog
outputs.
154
Signal name Message
Diag_2 Overload DO byte 5/4
Diag_1 Overload DO byte 3/2
Diag_0 Overload DO byte 1/0
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 switched off.
The value 0x80 is stored in status byte 1.
-
The "PNFault" LED is activated.
The outputs are switched off.
The value 0x80 is stored in status byte 1.
Selection of operating mode is rejected,
Remedy
It is essential that a Pt100 element is con‐
nected 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 Power
1)
ON after the error has been eliminated.
If selected correctly, the module switches
to cyclic operation.
Equipment Manual, 10/2021, A5E51087503B AA
NCU 1740