It is hopefully much less than 5% of the time the process is running, so that control is exercised. In that setting, the operator's role in managing the process could not be ignored.
Delay Fuse Plant—A powder mixing process produces a batch of fuse powder with a known rate of combustion. The powder is poured into lengths of lead tubing on a
A blasting cap consists of a drawn copper shell approx. 0.25" (6 mm) in diameter and long enough to contain the detonating ingredients, time delay fuse and plastic end plug. The main raw materials for the blasting cap plant processes are copper plate for the shells, bare copper wire for the leads, explosive and time delay powders, plastic for lead insulation and jacket plugs , and fine wire for the bridge wire that is heated and hardened. away from the explosives.
Loading and Pressing Bays—Shells are manually placed into 500-shell press blocks
Base cap assemblies that pass a bridge wire resistance check are boxed for transport to the final assembly machine. Delayed Fuse Plant—Powders manufactured elsewhere are selected according to a recipe and mixed to produce a batch of fuse powder that will burn at so many inches per.
Delay Fuse Plant—Powders made elsewhere are selected according to a recipe and mixed to produce a batch of fuse powder that will burn at so many inches per
A press does go through a sequence of operations to make products, but that alone is not enough to make it a batch process. Of course, the operator tells you that a "batch" of shells is done when the lid on the box is closed.
Loading and Pressing Bays—Empty shells are filled with measured amounts of powder according to a recipe, and they are pressed to compact the powder to a cer-
But more pellets are added to the process as plastic is extruded, and no sequence of operations is required to produce the product. Assembly plant—No question here: assembly machines that move a discrete part to different tooling stations (or vice versa) to make physical changes.
Assembly Plant—No question here: assembly machines that move a discrete part to different tool stations (or vice versa) so as to make physical changes are the
A continuous process may only have a few specified products and not call the specifications "recipes." An individual recipe may be referred to as a "Bill of Materials". The number of products a discrete process can make is limited by the degree of specialization of the machines. Some data can be changed by "executing" the block, but it must be remembered so that the block can be properly initialized after the processor reboots.
NAMUR
Structure for Batch Control
It is the basic control that can change and maintain the state of the process material (e.g. pressure, temperature, agitation, composition of reactor gas in the headspace). It is the basic control that can change and maintain the status of the equipment configuration (e.g. transfer header, heat exchange media). Basic control is performed with physical equipment in a way that is completely independent of the product being made.
The results of the basic check command may affect the execution of the procedure. An example of a procedure for a specialty chemical is an entity named "Terephthalic Acid Procedure". The process for the production of terephthalic acid (TPA) was used as an example in Chapter 2. An example of a Procedure for a biological process might be the Miraculomycin Procedure. The process grows cells that produce a miracle drug.
Equipment Entities
The model of the relationship of procedural control to controlled equipment to process functionality is fundamental to the 88.01 standard. The main purpose of the control associated with a unit is to execute that part of the recipe procedure assigned to the unit. The main purpose of the unit is to translate the recipe procedure into commands that can be given to the equipment entities that own or have acquired it.
The equipment module that contains everything else provides the interface to the unit, so everything else is hidden. The underlying modules can be exposed when the mode of the top equipment module is manual. An equipment module that serves as common equipment must be able to be the server side of the acquisition or release dialog.
Recipes
A master recipe is created for a single process cell using knowledge of the equipment entities within the cell. The control recipe process is a duplicate of the main recipe process unless someone changes the control recipe. The site recipe process is a copy of that part of the general recipe process that applies to the site.
The control recipe procedure starts as a copy of the master recipe procedure and can remain that way until the end of the batch. The procedural elements in the control recipe procedure must contain all information required for the operator interface of the corresponding controlled equipment. In a sense, the recipe stage serves an equipment stage, where operation means transferring the setup parameters to the equipment interface, "pressing" the start button, and receiving status reports.
Production Plans and Schedules
Specific equipment to use or an allowed selection to use—Affects the control recipe, if necessary. Edward A. Murphy researched high G forces by testing a rocket sled at Edwards Air Force Base in 1949. Murphy said, "If there's a way to get it wrong, he'll find it.".
Somehow this "law" has turned from an observation about people into an inexorable law of probability. Maybe it's because "If anything can go wrong, it will" sounds better than "Not my fault". John P. Stapp, the first to quote Murphy to reporters, came up with Stapp's Ironical Paradox, which says, "The universal predisposition to ineptitude makes every human achievement an incredible marvel."
Production Information
If the event is not detected and stamped at the source, the time may be offset by communication and processing delays in intervening machines. A copy of the final control recipe—The initial control recipe can be modified during the batch. Event data—The best thing to do with event data is to record everything available with timestamps and source identification.
If the process cell is small, then the group information flow can be captured on paper or flat files. It may be necessary to trace the genealogy of the group as well as its quality tests. Report formats or views can be changed to display different data without modifying batch history data, unless the data is not in history.
Allocation and Arbitration
The choice may depend on the connection with the following units to ensure the completion of the set. If the unit requests service from the resource without warning, then the resource may not be available. Some batch processes may request a resource for part of the batch's processing time, leaving the resource free to serve other similar processes.
In that case, the resource cannot be a device, but can be an equipment module. The use of the title can be determined by anything from simple assignment to pre-emption. Either way, when priority is exercised, the current occupant of the resource or a reservation slot must be preempted.
Modes and States
The header is clean and closed when the state machine is in the idle state. Something similar can be used to describe and perform procedural control, where the boxes represent procedural elements and the transition conditions are usually "Done". The SFC-like representation is covered in Section 6 Procedure Function Maps in ANSI/ISA. The state of procedural control is determined by a state transition diagram in the example used in Figure 18 of 88.01.
Procedural elements continue on their normal path until there is a transition to the next procedural element, when the state changes to Paused. Paused - Execution of procedural elements is paused at points between procedural elements so that a clean restart is possible, provided the mode is not changed to manual. Containment—The containment path normally stops all material and energy inputs to the process so that things do not deteriorate.
Exception Handling
Sometimes alternatives were presented, in the hope that SP88 would consider them for the next revision of 88.01. This recap of batch control history appears here to prepare you for discussion of the 88.01 Control Activities section that begins in the next chapter. If a header existed in the recipe, it might contain the source of the recipe.
For example, a formula can take the form of a list of parameters for control, but can include modifiers to. the processor its subordinate operations. The equipment layer was set outside the PRM "due to large differences of equipment and functions between different industries." The enterprise level was "considered an external entity" because it was agreed that a high level of creativity was required, higher than any computer would ever be capable of performing. This chapter has reviewed the changes to the fundamentals of batch control over the years as a basis for the discussion of the control activities in Section 6 of 88.01, which will be discussed in the next chapter.
Control Activities
There are only seven group process control activities, and one of them is outside the scope of the standard. Production Planning and Scheduling – The functions of this activity are divided between business and production. Information management - Information from the operation of the process cell must be stored somewhere.
Three of those clouds were apparently attached to the top of the cactus and its arms. The control activities must prohibit unauthorized changes so that there is no one who is unaware of the change. The reasons for the change and the methods of making it must be documented and linked to the version number of the changed information.
Recipe Management
Manage the process of changing procedural elements, including conducting a thorough assessment of the effects of the change. Some sellers or users may require that the prescription procedure on the site be identical to the general prescription procedure. This function is similar to that for the general recipe elements, except for the names and usage of specific equipment entities.
Each master recipe building block must have a counterpart in an equipment item at the point in the procedural element hierarchy where a recipe procedure item is implemented by an equipment procedure item. Automatic translation of a general to a master recipe procedure requires that one or a set of master recipe building blocks must have the same process functionality as the matching general recipe building block. Manage the procedural element change process, including conducting a thorough review of the effects of the change.
Production Planning and Scheduling
Production Information Management
Information is collected by the Process Management, Unit Supervision, and Process Control activities, which send their information to the Production Information Management activity. Interoperability can be useful here and can be provided by OPC or a suitable fieldbus system. Time relative to the start of the batch or the start of an identified procedural element.
Identification of the person who entered the data if not done by a tagged device entity. The archive can be a greater storage function in business data systems than a vault locked away in a basement somewhere. People will want to know what is in local storage and what is in remote storage.
