PLC's
PLC's
(OP)
What is the difference between sychronous and asychronous when referring to types of PLC's? Can someone explain.
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RE: PLC's
"Venditori de oleum-vipera non vigere excordis populi"
RE: PLC's
Synchronous being that the outputs are updated (turned off or on) at the end of each scan.
Asynchronous meaning that the outputs can be turned off/on at any point during the program scan (maybe similar to an interrupt).
RE: PLC's
Regards,
Jacek
Do it right or don't do it at all.
RE: PLC's
The backup processor doesn't always "process the I/O" or execute the program. In some systems, the I/O is scanned and stored only, until a fault is detected in the primary processor. THEN the backup immediately begins executing its program. This may cause a slight delay (one or two scan cycles) in backup. It's useful if the backup program is different than the primary. Sometimes, at least.
I'm sure different vendors use the terms in their own way, as well.
. . . Steve