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Block Transfers in PLC-5 whether local/remote work in an asynchronous fashion. This implies the data as well as the status bits (Done, Enable, Start, etc) are asynchronous to the PLC-5 program and I/O scan. Recommended thing by many sources is to copy the data and the status bits to another set of registers (i.e. buffer area).
1rst, where in the program scan do I copy this data to the so called buffer area?
My problem is: I need to know when fresh data has
arrived from speciality I/O which includes VHSCE, motion controllers (QB), Analog input cards, etc. I am running a motion application and that application requires continous motion.
My other major problem is I need to know when fresh data comes in perfectly (very critical that I can not have old data in there since I am performing extensive math in the PLC).-I can not just use the done bit because it remains on until enable bit goes on again and I really need the scan time so I prefer not to slow it done too too much by using other items like one-shots but if only solution, please let me know.
From one integrator to the other or user, I would greatly appreciate it if you can shed some light on this matter.
Thank you so much.
Kind Regards,
[email protected]
1rst, where in the program scan do I copy this data to the so called buffer area?
My problem is: I need to know when fresh data has
arrived from speciality I/O which includes VHSCE, motion controllers (QB), Analog input cards, etc. I am running a motion application and that application requires continous motion.
My other major problem is I need to know when fresh data comes in perfectly (very critical that I can not have old data in there since I am performing extensive math in the PLC).-I can not just use the done bit because it remains on until enable bit goes on again and I really need the scan time so I prefer not to slow it done too too much by using other items like one-shots but if only solution, please let me know.
From one integrator to the other or user, I would greatly appreciate it if you can shed some light on this matter.
Thank you so much.
Kind Regards,
[email protected]