Read heading offset

hi !!

i´m reading the heading value in lua script by offset and then increments 1 and write new value like that:

Heading=ipc.readUW(0x73c3)
Heading=Heading+1
ipc.writeUW(0x73CC,2)
ipc.writeUW(0x73CD,Heading)

i´m incrementing the value from encoder but when the ipc.read executes the refresh in heading slow down. i found that the intruction ipc.readuw(0x73c3) takes some time and the refresh rate slows down on the fcu interface of fmgs. any ideas??

thanks very much!!