When a program in the source controller keeps setting a point's value to the same value (i.e. set MyPoint = On) every scan, the point's value is being transferred to the destination controller even if the point is subscribed in the Import/Export table.
Infinet controllers ( i1 & i2 )
Net controllers ( CX9xxx & ACX57xx)
When the value of the source point is changed, it is transferred to the destination Infinet controller(s) by the IE engine. But when the source point's value is set to the same value (most likely output and numeric points set by calculation programs in the same controller), the IE engine still transfers the same value to the destination controller, in order to have the destination controller get the value that might have been lost due to the controller being offline. This does not happen to Input points due to the threshold attribute of the object.
Modify the calculation program in the source controller to compare its value with the previous value before setting the value to the calculation (or condition check) result.