Hi,

no it is not necessary ...

acquisition cycle is the update time of your tag for it can be  1sec or upon change.

for eg .if u keep acquisition cycle as 10 sec and if u monitor in your screen it will be updated every 10 seconds only...the change in value in between  10sec will not be updated.

and logging cycle time is the time delay of the tag u want to log...it can be for every one hour or every min...