HEIDENHAIN PROFIBUS-DP (DPV0) - Manual (Page 51)

Encoder and Gateway functionality, DPV0
51
5.6.9 Warnings
Warnings indicate that tolerances for certain internal parameters
of the device have been exceeded. Contrary to alarms, no faulty
position values are expected in case of warnings. Octets 20 and
21 of the diagnostic function indicate the status of the warnings.
If a warning is set, the Ext_Diag bit in the diagnostic function is
logically set to 1 until the warning is cleared. All warnings are
deleted when the diagnostic message of the device has been
read. However, if the tolerances are still exceeded, the warning is
activated again. The warning “Maximum operating time exceeded”
(bit 4) is not activated before the system is switched on again.
Note:
Not every encoder supports every warning.
Please refer to the diagnostic information under
“Supported Warnings”, see chapter 5.6.10, for
information on the support of specific warnings.
Octet 20 21
Bits 15-8 7-0
Warnings
Octet Definition =0 =1
0 Frequency exceeded No Yes
1 Temperature exceeded No Yes
2 Light control reserve Not reached Reached
3 CPU monitoring status OK Reset
4 Maximum operating time
exceeded
No Yes
5 Battery charging OK Too low
6 Reference point Reached Not reached
7..15 Currently not assigned
Table 29 Diagnostics, warnings