Representation of the analog values of analog modules
5.9 Interrupts of analog modules
S7-300 Automation System Module data
5-36 Manual, 08/2006, A5E00105505-04
Note
Note: the system does not generate a hardware interrupt if your limit setting exceeds the
overshoot or undershoot range.
Structure of the start information tag OB40_POINT_ADDR of OB 40
The information showing which channel has violated which limit is entered in the
OB40_POINT_ADDR tag of the OB 40 start information. The figure below shows the
assignment of bits in DWORD 8 of local data.
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/% /%/%
%LWQR
9DOXHIDOOVEHORZORZHUOLPLWLQFKDQQHO
9DOXHIDOOVEHORZORZHUOLPLWLQFKDQQHO
9DOXHH[FHHGVXSSHUOLPLWLQFKDQQHO
9DOXHH[FHHGVXSSHUOLPLWLQFKDQQHO
Figure 5-6 Start Information of OB 40: Which event has violated limits and triggered a hardware
interrupt
Hardware interrupt triggered by "Reached end of scan cycle"
A hardware interrupt programmed to be triggered at the end of scan cycles allows you to
synchronize a process with the scan cycle of the analog input module.
A scan cycle includes the conversion of the measured values of all active channels of the
analog input module. The module processes the channels in succession. When all measured
values are successfully converted, the module reports the existence of new measurement
data at its channels to the CPU by means of interrupt.
You can always use this interrupt to load the actual, converted analog values.