Mode & Command as Integer, a Serious Issue

Hi,
I am working on a very good project to make standard of everything in the project.(Pharma Industry).We have Basic control module(CM) which is standard FB controlling Valve, Motor..etc , And then we have Equipement Module(EM) which is Upper level of CM controlling combination of few different/similar CMs. EMs are also programmed in FB. Then Unit level which is controlling few EMs that belongs to the Unit.Then finally Recipe which is calling Units to start/stop.

Many of EM/Unit/Recepe running with Sequencer.They have different mode of operations, at this moment Auto, Manual and Out of Service.But client may add another mode later.So we are using a Integer Variable as Mode.Then again we have Command which is again Integer though we are just starting or stoping by the command, as per client they can add few more command later.( Though I am not sure what will be that command).Now picture is quite straight forward-

Each Control module must be able start/Stop in manual mode.In auto mode EM will start/Stop CM.But it is also possible to change mode of CM from auto to manual while EM is running (Only few case is like this).This is my first problem- Still not sure & safe way to do this. Similarly in EM level EM Sequencer can start/stop another EM. Similarly Unit also can start/stop the EM. I am here just to see if you guys have any other solutions.

What I am doing is like this:
Chech Command/Mode in each scan if any change in Mode/Command then only act accordingly.Checking of this logic is done at the begining of each EM/Unit.

I understand the description of your system.

What's not clear is exactly what your problem is.

If you would like comments on your approach, you need to post some code.

To the question of Integer vs Bits for mode (I think that's what you are asking), Integer has one major advantage: It is impossible to be in two modes at once. With bits, you have to code to avoid this.

First, how is your understanding of ISA S88.01? Among a lot of other things it provides some examples of modes and states. But it is not definitave.
Are you using a batch manager eg InBatch or RSBatch. If so you need to understand Phase Logic Interfaces for a start.
Even if you are rolling your own Batch Manager, eg in PLC Logic, you need to have consistent modes and states, generally this is something that you would not change.
Take a look at s88control.blogspot.com for a lot of discussion and some links to other sites that deal with the issues.
Francis