SIMATIC BATCH Dynamic Material Routing: Passing Process Values to Equipment Phases for Silo Selection and Recipe Starts

To enable SIMATIC BATCH to dynamically route materials from process silos and start recipes based on live plant conditions, use SIMATIC BATCH Material Management coupled with Equipment Phase (EPH) Process Parameters. Define raw materials in the Batch Control Center (BCC) and assign them to specific storage locations (silos). In the recipe, configure an equipment phase parameter for source silo identification. The AS acquires silo selection or inventory levels from field transmitters and writes them into the SFC Type interface inputs (BA_ID, STEP_NO, and technological parameters). SIMATIC BATCH coordinates dosing setpoints dynamically based on the active silo parameter.

Dynamic Storage and Silo Allocation in Recipe Operations

In bulk materials processing, compounding plants, and food manufacturing, raw ingredients are frequently stored across multiple silos or tanks. A recipe requires a specified quantity of raw material (e.g., 100 kg of Material A and 200 kg of Material B). However, which specific silo contains Material A or has sufficient available stock varies dynamically across production shifts.

There are two primary architectural methods to achieve this in SIMATIC PCS 7 and SIMATIC BATCH:
1. BCC Material Management with Storage Location Allocation: SIMATIC BATCH determines the silo at batch creation or runtime based on tank inventory.
2. Process-Driven Parameter Transfer (AS to BATCH): The PLC monitors silo level transmitters and valve statuses, passing the selected silo ID into the batch execution sequence as an input process parameter.

SIMATIC BATCH Material and Tank Management Architecture

SIMATIC BATCH provides integrated Material Management within Batch Control Center (BCC):

Materials and Qualities: Each raw ingredient is defined with an alphanumeric identifier, technological code, and physical properties.
Storage Locations: Each silo is registered in the BATCH database as a storage location belonging to an Equipment Module (EMOD) or Unit.
Dynamic Allocation: When a recipe step executes, SIMATIC BATCH evaluates recipe material requirements against available storage locations. If Silo 1 contains Material A, BATCH automatically routes the setpoint to the equipment phase controlling Silo 1 discharge valves.

Configuring SFC Type Parameters for Silo Routing and Setpoints

When implementing technological phases via SFC Types:

Open the SFC Type in the Engineering Station.
In the Characteristics dialog, define recipe parameters:
- Target_Silo_ID (Data Type: INT or DINT): Specifies the selected silo (1 to 6).
- Dose_Quantity (Data Type: REAL): Specifies target discharge weight in kilograms.
- Actual_Dosed_Weight (Data Type: REAL, Characteristic: PI - Process Input): Transmits real-time dosed quantity back to BATCH.
In the SFC Type sequencer logic, evaluate Target_Silo_ID:
- If Target_Silo_ID == 1, energize feeder drive 1 and open discharge valve 1.
- If Target_Silo_ID == 2, energize feeder drive 2 and open discharge valve 2.
Compile the SFC Type and generate block types into the project.

AS-to-Batch Communication via BATCH Interface Blocks

For scenarios where the AS must trigger recipe execution or select silos based on field instrumentation:

BATCH Interface Blocks: Utilize standard blocks such as BATCH_INTERFACE (or custom event triggers via WinCC OLE-DB / BATCH API).
SFC Type Interface: The standard SFC Type incorporates standard pins (BA_ID, BA_NA, STEP_NO, OCCUPIED, QBA_ID). When BATCH starts a recipe phase, it writes the batch identification into BA_ID and activates the phase.
Process Value Synchronization: The SFC logic reads the AS process tag (e.g. Selected_Silo_Number) and maps it into an internal setpoint or returns an error if the selected silo contains insufficient inventory.

Material Routing and Process Feedback Architecture Matrix

The following table compares dynamic routing strategies in SIMATIC BATCH:

Engineering MethodS7-400 Logic RoleSIMATIC BATCH RoleOperator FlexibilityBest Suited ApplicationMaterial Management (BCC)Direct execution of selected phaseTracks silo inventory and assigns equipmentHigh (managed via BCC GUI)Complex multi-product bulk plantsParameterized SFC MultiplexerEvaluates Silo_ID input to switch drivesSupplies Silo_ID integer setpointModerate (recipe setpoint selection)Dedicated multi-silo dosing systemsBATCH API External TriggerAS generates recipe start triggerSchedules and launches batch on signalAutomated (no manual BCC intervention)Continuous-batch hybrid unitsUnit Allocation StrategyExecutes single silo phase per unitBinds unit based on raw material availabilityHigh (automatic unit selection)Tank farms and large storage halls

Implementation Workflow: Dynamic Silo Unloading in SIMATIC BATCH

Follow this configuration procedure to implement parameterized silo unloading:

Define SFC Type Characteristics: Open the unloading SFC Type. Add SP_Silo_Number (INT) and SP_Dosing_Weight (REAL) as setpoint characteristics. Add ACT_Dosed_Weight as a process value characteristic.
Implement Step Logic: In the SFC Type sequencer, insert routing steps: Step 1 evaluates SP_Silo_Number. Branches lead to independent sub-steps energizing Silo 1 through Silo 6 feeders and scales.
Compile and Download AS: Compile CFC/SFC and perform download to the S7-400 controller.
Propagate to SIMATIC BATCH: Open SIMATIC BATCH engineering in SIMATIC Manager. Perform Generate BATCH Types and Compile / Download BATCH.
Create Master Recipe: Open Batch Control Center -> Recipe Editor. Insert the unloading Recipe Operation. In the phase parameters, enter the target weight (e.g., 100 kg) and assign the desired Silo Number (e.g., 1 or dynamic formula).
Release Recipe and Validate: Release the master recipe, create a test batch order, and verify that the correct silo is energized.

Verification

Validate dynamic silo routing using these methods:

BCC Parameter Verification: In Batch Control Center, inspect the active batch control window. Verify that SP_Silo_Number reflects the recipe setpoint.
AS Online Monitor: Open the instantiated SFC chart in CFC test mode. Confirm that Target_Silo_ID receives the setpoint value from BATCH.
Physical Valve/Drive Activation: Ensure the corresponding field drive (e.g., Silo 1 discharge rotary feeder) activates while silos 2–6 remain de-energized.
Batch Report Audit: Verify upon batch completion that the generated Batch Electronic Report records the actual silo utilized and total dosed weight.

Limitations and Operational Precautions

Consider these operational constraints:

Silo Interlocking: Controller logic must enforce safety interlocks independent of BATCH. If a selected silo level is below low-low threshold or discharge gate is faulted, the SFC must generate an operator prompt or hold state.
Concurrent Silo Allocation: If multiple batches attempt to draw material from the same silo simultaneously, configure Unit/Equipment Module allocation rules in BATCH to prevent resource contention.
Commercial Accuracy Disclaimer: Software order numbers (MLFBs), package structures, and hardware capacity prerequisites vary across PCS 7 versions and hardware platforms. System integrators must confirm exact software entitlements and licensing requirements against the official Siemens Catalog CA 01 and obtain an authorized Siemens distributor quotation prior to purchasing.

Engineer FAQ

Can SIMATIC BATCH automatically select the silo based on lowest remaining material?

Yes, if using SIMATIC BATCH Material and Tank Management with automated allocation rules, or by having an AS function block evaluate silo levels and supply the selected Silo_ID to the batch interface.

Can I change the silo assignment while the batch is running?

If the recipe phase allows online modification of setpoints, an authorized operator can pause the phase, adjust SP_Silo_Number, and resume dosing.

Does dynamic silo routing require an additional SIMATIC BATCH license?

Material management is included in standard SIMATIC BATCH server packages; however, advanced tank farm management may require the SIMATIC BATCH Material Management option.