Hi,
i am programming in ladder whit opta and PLC IDE.
I need to read the in put of 6 differend board connected via modbus RS485
The modbus reading function can be inserted only in the background task that it is scheduled everey 500ms so to read the six board i need more to 3 second. it is too much dealy for my application.
there is a metod to increase the speed of the reading in ladder whit opta ?
Best Regards
Stefano
Your calculations are supposedly wrong.
If each of the tasks scheduled every 500ms, it's not mean that six task will needs 3 seconds, it needs a slightly more than 500ms, because all of the timeouts counts in parallel.
Hi,
thanks for te reply.
I cant do the reading at the same time, if i do that i have an error on the modbus reading.
At this time i can do only one reading every 500ms.
I have try to modify the "wait befor send" but i have the same error.
how i can do multiply "simultaneuos" reading in about 500ms ?
Although you can't "simultaneous reading", you definitely can "simultaneous waiting".
So, after you finished reading a first board, set an alarm for 500ms for it and immediately start reading the second. Then set another alarm and start third reading... and so on.
The idea that you should not include a waiting time inside a reading procedure.
Hi,
i have tried to program alarm to “schedule“ the reading. I set a variable that increase avery second and enable each reading one at time.
But i have the same problem, i have an error on the reading.