Actual refresh rate CP651 with ABB CodeSys ETH protocol
I have a CP651 which is communicating with several AC500 controllers. I am using the ABB Codesys ETH protocol for this. Does anyone know how the CP651 panel is calculating his actual refresh rate of his tags? Is this as fast as possible? And what is the consequence for the CPU load en RAM usage of the panel when there are a lot of tags with changing data?
This is what the manual says:
WARNING: Tags refresh rate is the maximum refresh rate. Actual refresh rate depends on: communication type (serial, fieldbus, Ethernet), protocol, amount of data exchanged.
I think there is no exact calculation or definition of refresh rate, may be nobody will fix such parameter, because it depends on so many factors.
From my experience, when you have ETH and CP6xx, the refresh rate is a quite fast. Of course, havig a reasonable number of "live" fields on the screen.
Normally, only the tags, placed on currently open screen (active screen) are updated, and not all the tags, defined in the proect.
But - tags, used in logs (trends for example) are updated every time when have to be saved (defined in sampling time). In case you need faster refresh rate of screen, don't use so many logs and try to use longer sampling times.
That is valid also for other special functions and services, as it is described in the manual.