Hardware Interrupt Evaluation - Siemens SIMATIC CM35 Manual

5.5

Hardware Interrupt Evaluation

CM35 Counter Module
(4) J31069-D0416-U001-A5-7618
When in ²pulse counter² mode, the CM35 can trigger a hardware interrupt
when a comparison value is reached. If this is used, the CPU must contain a
hardware interrupt OB (OB 40).
The start information of OB 40 contains the following information.
- - The variable OB40_MDL_ADDR contains the base address of the
module which triggered the interrupt.
- - The variable OB40_POINT_ADDR contains information on the event
which caused the interrupt.
The variable OB40_POINT_ADDR consists of four bytes. The hardware in-
terrupt information of the CM35 in ²pulse counter² mode is entered in the
low byte (local byte 11 of OB 40).
By evaluating local byte 11, you can determine which channel triggered the
interrupt. Remember that more than one bit can be set.
Table 5-14 Assignment of the hardware interrupt information (OB 40/local byte 11)
Local Byte Bit
11 0 Counter 1 has reached comparison value.
1 Counter 2 has reached comparison value.
2 Counter 3 has reached comparison value.
3 Counter 4 has reached comparison value.
4 Counter 5 has reached comparison value.
5 Counter 6 has reached comparison value.
6 Counter 7 has reached comparison value.
7 Counter 8 has reached comparison value.
Pulse Counter Operating Mode
Meaning Value Range
0/1
5-17