With the add-on Plant Liqu iT Routing Management rule-based routing orders with a dynamic route search and allocation can easily be integrated into order processing.
A user program in a PLC searches for a route to drain a tank. For this the user program creates an order with rule-based routing. The routing order then automatically selects a suitable target tank, starts the order and controls the sequence with the appropriate recipe. A route consists of the following plant sections and routes:
- Source plant section
- Source route consisting of up to four line sections
- Main route consisting of up to four line sections (optional)
- Target route consisting of up to four line sections
- Target plant section
Moreover, the add-on offers the possibility to use routes or a part of the routes already planned in the sequence FIFO for the route engineering.
A sub-folder for rule-based routing orders is available for each process area. This folder contains a route matrix in which the existing routes are planned per sequence. Several routing rules can be defined for a rule-based routing order. In a routing rule the way how to process the routing process and how to start the order in the Operation Manager is specified. The routing rule also determines the order template. The order template in turn determines the sub-procedure to be started from the recipe or procedure.
The engineering of routing processes requires a basic parameterisation of sequences with respective FIFO objects (First In, First Out) and a suitable order template. A procedure or a recipe to be started by the routing process must be available as well.
The Routing Management is operated via the central user interface of Plant Liqu iT - the Operation Manager. When using the Routing Management the following dialogues are extended with additional tabs:
- Order list: the “Routing" tab is added in the detailed information on the selected order. It displays the route and manual release, if required, takes place in this tab.
- Order processing: the “Routing” tab is added. It displays the route matrix and in case of manually created routing orders, the source, target and route are selected in this tab.
The user program in the PLC transfers the number of the routing rule to the Plant Liqu iT server. The server then calls a database procedure which creates an order and starts the route search. This order is added to the order list with the status “Basic position”. Once a route has been found, the order status changes to “Waiting” and waits for the start.
An order with rule-based routing can also be created manually. For this an already existing order template has to be allocated to a routing rule. By means of the Routing choices are limited and operators are supported. In the "Routing" tab of the order in the Operation Manager, operators either select the source plant section or the target plant section. Subsequently, routing determines the available target and source plant sections and routes. All available objects are highlighted via a green flashing arrow. After specifying the route the order can be started. As long as the order has not been started, operators can reset and change the selected route.
In order to prevent the same plant and line sections from being simultaneously allocated to severeal routing orders, the corresponding route objects (plant and line sections) are automatically reserved for the respective order as soon a a root has been found. For this purpose, a routing rule can be queried in the selection criteria to find out whether a plant section or individual line sections are reserved for a rule-based routing order.