Due to its rich set of standard features, SCMs greatly simplify batch logic implementation. The SCM implementation follows the S88.01 standard. Standard features include abnormal handling, providing an alternative sequence execution for user specified abnormal conditions. Abnormal handlers support restart capabilities, re-starting the sequence from the position it was left or any other Step the process requires to continue. Standard Abnormal handlers include: Checking, Interrupt, Restart, Hold, Stop and Abort. Each sequence supports up to 50 recipe parameters. These include a range, material code and scale option. In addition, it has 50 history parameters for reporting the amount of actual dosed material and/or reached process conditions. The mode track option allows for different operating philosophies. Devices, such as motors, pumps, and controllers, will follow SCM mode changes allowing either operator or sequence device control. The devices can also be pre-configured with the action required after an SCM start, abnormal situation or restart. This reduces the SCM step configuration.

 

 

One feature of particular importance is the Common SCM function. A Common SCM is one that can control several equipment units, one at a time, depending upon the unit selected. It saves implementation, test and maintenance time required to support the application. The selected unit may be determined at configuration time or changed dynamically during run time. An example application might be header dosing in a batch plant. SCMs, including this Common SCM function, are fully integrated into Honeywell’s TotalPlant Batch package for flexible batch operation.