Controlling Batch Runs

Batch Procedure ISA-88 Based Communication Model

This information details the command and state lifecycle within the Sepasoft Batch Procedure module. The communication model is fundamentally based on the ISA-88 standard for batch control, a widely adopted framework for designing and implementing flexible and modular batch manufacturing systems. A thorough understanding of this model is critical for engineers responsible for interfacing the batch execution system with Programmable Logic Controllers (PLCs) and ensuring the robust, reliable execution of batch recipes.

The primary method for communication between the Sepasoft batch engine and a PLC is the Phase Logic Interface (PLI). The PLI defines a standardized structure for the tags used to pass data, such as commands, states, and process parameters, back and forth between the two systems. The core principle of this model is a clear division of responsibility: the Batch Engine is the master of what to do (Commands), while the PLC is the master of its own condition (State). This ensures that both the high-level recipe execution engine and the low-level equipment control logic operate in a synchronized and predictable manner.

At the core of this model is the relationship between Batch Equipment Phases (defined in the recipe) and the equipment phases implemented in the PLC). There is a direct, one-to-one mapping between them. For instance, a batch phase named "Add H2O" in a recipe corresponds to a matching "Add H2O" equipment phase programmed in the PLC. This direct correlation simplifies logic development and troubleshooting by creating a clear and consistent structure.

• The Core Components: Commands and States
• Batch Procedure Component to Control Batch Runs
• Initiating Batches from an Enterprise Gateway
• Batch Execution Modes
• Phases that Support Execution in Manual Mode
• Batch Running in Auto Mode
• Phases that Support Force Complete
• Messages during Batch Execution
• Enterprise Network and Site Configuration by Script
• Sync Group Handshake

Batch Procedure Component to Control Batch Runs

Batch Procedure components and scripting functions to add and run batches:

• Batch List
• Batch Recipe Monitor
• Batch Controller
• Batch Procedure scripting functions: system.mes.batch.queue

Initiating Batches from an Enterprise Gateway

The root gateway server within an MES Enterprise Gateway Network can initiate batch commands on child gateway servers. For more info, see MES Enterprise Network.

Phases that Support Execution in Manual Mode

Batch Procedure Phases

• Document
• Equipment Phase
• Script
• Set Parameter
• User Message
• Value Prompt

Batch Running in Auto Mode

This is a summary of a Batch Recipe Mode set to Auto and each phase in the recipe has its State_Transition_Handling parameter set to PLI.

Once a batch is started and a phase becomes Active, these actions happen:

When a batch is running, there is a one-to-one relationship between the Unit Procedure in a Batch Recipe and a Unit within the Equipment Model. The Unit is allocated to the Unit Procedure when that Unit Procedure step becomes Active.

• Batch sends Output Parameters and the Start command to the equipment.
• The equipment sends back the Running state.
• Parameters values can change.
• Equipment sends read-only Input Parameters.
• Depending on the Recording Type property, values are recorded to history.
  
  

Expand to learn about the Recording Type property

Parameter Properties

Depending on the phase and scenario, a property may be read-only.

Property Name	Options	Description
Recording Type	All to History	Parameter values on a regular update-interval are recorded to the database for MES Analysis use.
	All to Object	Parameter values are saved against the MES Objects to ensure continuity of operation in case of power outage or server restart.
	All to Object and History	Parameters are saved to both the object and history.
	All to Object and Last to History	See “All to Object” above.  Last values indicate only final parameter values are saved to history DB tables for analysis.  For example, rather than an accumulated counter for quantity, only the final quantity would be recorded.
	Changes Not Saved	Parameter values are not recorded.
	Last to History	Parameter values are saved at the end of the phase to the DB for exposure to analysis.
Value Source	Recipe	Gets the value from a recipe parameter before the batch starts.
	Execution	Gets value at runtime, once the batch has started. Runtime options are: the parameter value set in phase configuration, tag engine, and scripting.
	Recipe and Execution	Gets the value before the batch starts AND gets  the value at runtime, once the batch has started.
	Monitor	Captures values from the equipment. Configure tags for history timeframe.  When selecting Monitor, the parameter value becomes read-only, and a default value will not be set. The system checks every 100 milliseconds but only writes changes to history when the value changes. Monitor is intended for listening and recording in history values from the PLC. An example is Actual Temperature (PV_Temp) where the PLC has complete control of changing the value and the Batch Module only listens and records the value. Only accessible in Phase Manager.
	Synchronization Manager	Set on the receiving phase within a Sync Group of Synchronize Phases.
	Neither	These are parameters used internally by the Batch engine and cannot be changed via UI nor scripting.
Tag Type	Memory	Parameters are instantiated in the Phase UDT as memory tags.
	OPC	Parameters are instantiated in the Phase UDT as OPC tags.
	Reference	Parameters are instantiated in the Phase UDT as reference tags. You can set source tag paths for remote tags. For example: Add a new parameter to a phase and set the Tag Type to Reference. Do the same for the State parameter. Edit the phase UDT and set the Source Tag Path (to a referenced tag) for the parameters that were set to Reference tag type.
Calculation	Expression	Used for reference to another field or parameter OR when a unit of measurement needs to be calculated. Single line of Python. This is a function that is injected into a system Python. (Not available with the ENUM data type.) Start with a forward slash to set a path from the root of the procedure or recipe hierarchy.  param(“/{}.Unit_Path”) This means get the value for the Unit_Path parameter one level above the active object. Use curly brackets to set at the current level within the hierarchy, e.g.,  param(“{}.Unit_Path”) This means get the value for the Unit_Path parameter for the active object. See Parameter Expressions.
Data Type		Possible Data Types Data Type Boolean See Data Types and Formats. Byte Date Double Enum Float Integer Long Material In Set of sub-parameters for tracking material. Material Out Set of sub-parameters for tracking material. Short See Data Types and Formats. String Supplemental Equipment Set of sub-parameters for tracking equipment used in a process.

When a Transition evaluates to True, Batch Engine sends the Stop command.

• Equipment responds with Stopping, and then Stopped
• Phase Completed.
• Operation and/or Unit Procedure Complete depending on the recipe structure.
  
  

Batch Engine sends the Reset command.

• Equipment sends Resetting and the Idle.

Phases that Support Force Complete

• Timer
• Equipment Phase
• Synchronize
• Transfer In
• Transfer Out

Messages during Batch Execution

Operator messages and messages coming from a PLC can be viewed in Batch Message List and Batch Controller.

• Batch Message List 

Enterprise Network and Site Configuration by Script

In an enterprise network, you may want to add batches to a queue on a child site server via script.

See:

• Adding Batch Queue Entry and Specifying a Process Cell

Sync Group Handshake

See Synchronize Phase.

Sync flags are set either by the batch system or manually.

If setting manually, make sure to set them after a Reset command is received from the batch engine.

A  Sync_Mode = Auto   sets the  Sync_Flag_Complete = True   .

When all the phases within a  Sync_Group   have   Syn_Flag_Complete = True   , then the  Sync_Confirm_Complete = True   .

When the Phase sees  Sync_Confirm_Complete = True   , it sets  Complete = True .