The Batch block groups entities so that they flow together through a simulation model. Entities arrive at a Batch block individually through its InEntity input entity port. The Batch block holds the entities until the number of entities it is holding reaches the value that is specified in the Batch block’s batch size parameter. At this point, the Batch block attaches the held entities to a carrier entity and attempts to send the carrier entity out through the OutCarrier output entity port. The carrier entity carries the batched group of entities through the simulation model, but only the attributes of the carrier entity are accessible by other blocks. That is, the attributes of the entities that are included in the batch are not accessible by other blocks. Downstream in the simulation model, an Unbatch block can be used to separate the individual entities from the batch carrier entity. At that point all unbatched entities have their original attributes.

If nothing is attached to the InCarrier input entity port, a Default entity is created and used as the carrier entity whenever a batch of entities is ready to be sent out through the OutCarrier port. If there is a connection to the InCarrier port, the entities that arrive at that port are used as the carriers. If there is a connection to the InCarrier port, the Batch block waits until it has both a carrier entity and a complete batch of entities before it attempts to send the carrier entity out through the OutCarrier port. The Batch block can hold only a single carrier and a single batch of entities at any given time. Therefore, if there is a connection to the Batch block’s InCarrier port and the Batch block is holding a carrier entity but is not holding a complete batch of entities, the Batch block does not accept another carrier entity through its InCarrier port. Similarly, if there is a connection to the Batch block’s InCarrier port and the Batch block is holding a complete batch of entities but is not holding a carrier entity, the Batch block does not accept another entity through its InEntity port.

The InSignal input value port is used to force the Batch block to send out a carrier regardless of the number of entities it is holding. If a true value arrives at the InSignal port, the Batch block attempts to attach any entities it is holding to a carrier entity and send the carrier entity out through the OutCarrier port. In this case the carrier might not hold any entities or it might hold a smaller number of entities than the batch size. If there is a connection to the InCarrier port and a true value arrives at the InSignal port but the Batch block is not holding a carrier, the signal is ignored. A false signal arriving at the InSignal port is always ignored since it signifies that no action needs to be taken.

An integer value can be pushed through the InBatchSize port to set the batch size for the Batch block. If the batch size is decreased while the Batch block is holding more entities than the new batch size, the existing entities are batched together according to the new batch size, and the Batch block attempts to send a carrier entity out through its OutCarrier port for each smaller batch of entities. If there is a connection to the Batch block’s InCarrier port, the Batch block waits for a carrier to arrive before sending out each smaller batch of entities.