S7-400 CPU Memory Usage

I installed a particular S7-400 PLC in India about 3 years ago.
It is 6ES7 414-2XG03-0AB0 having work memory 128kb Code and 128kb Data.

I have my original Step7 project and would like to know how much code I can add as the customer wants some additional PID controls.

I have downloaded the original project to my Test PLC which is a
6ES7 414-2XG04-0AB0 having work memory 256kb Code and 256kb Data.

Under Module Information / Memory I find that in this (Test) PLC the program is using 151006 bytes for Code and 42,564 bytes of Data.

This Code size of 151006 bytes seems to be in excess of the code size of 128kB (= 131072 bytes) available in the running CPU.

Can anybody help me work out how much free Code memory there is in the installed CPU?

Hello John;

If you look at the properties of the Block folder (under Program) Simatic Manager will show how much code your program uses in work and load memory. Remember the critical element here is work memory, which can't be upgraded in these CPUs.
Hope this helps,
Daniel Chartier

Thanks Daniel,
I never thought to look there before.

It says Size in work memory CODE 119422 bytes so I figure I
have 131072 - 119422 = 11650 bytes free for additional code.
This should be just enough for my 8 additional PID loops.

However, I still don't understand why when I load the project to the later CPU the CODE takes up 143792 bytes. Any ideas?

Sorry, John,

Couldn't really say. I've never come up with that particular problem.
Maybe someone with more hardware savvy can shed some light on the subject.
Daniel Chartier