CMX Sequence and Batch Control is Unit Based

Up to 10 Units (ANSI/ISA S88 compliant) can be configured in the CMX Process Control System.  A Unit contains multiple Sequence Control Language (SCL) programs that run independently and/or interactively while coordinating and facilitating a process.

Each SCL program can direct two different types of Unit operation:

• Time-driven Control:  Used for the normal sequential operations of a process Unit, such as material charging and profile control. 
• Event-driven Control: is used to deal with unexpected events within the plant or process Unit, such as the failure of a valve that controls the supply of cooling water to a reactor.

In addition to responding to events in the process, the logic of an SCL program can also respond to Operator commands entered at the console. Every sequence-control program has available to it a library of recipes. Each recipe is a collection of numerical values associated with the process being controlled by the program. The use of a recipe, external to the program, affords the Application Engineer the opportunity to modify the quantities, times, temperatures, etc. used in the process without having to recompile the program for every such change. Up to five SCL programs can be concurrently controlling each process Unit, allowing independent control of individual sections or a Unit, such as the charging and overhead sections. To coordinate their efforts, programs can pass data among themselves by using a common area of computer storage.