Batching, Frequently Asked Questions
The PLC, or Programmable Logic Controller, is an industrial controller that was developed for many different automation tasks. These run from sequencing traffic lights to controlling huge petrochemical plants. It uses some of the fastest microprocessor chips, identical to those used in many computers. However, it has no rotating hard drive to wear out, no Windows operating system and has been designed for a life exceeding 20 years in rough, tough industrial applications. Because it does not use Windows, it is immune to the problems you see in your own computer from time to time.
Programs that run in your PC computer are sequential. They complete tasks in a set order, branching along the way when they make decisions. There are thousands of branches in a typical program and if only one of these branches is a dead end, the program stops or “freezes”. Sounds familiar? In comparison, PLC programs run in an endless loop like a wheel turning, repeating hundreds of times every second. Every time around, they check all the inputs, make decisions based on the program in the loop and set all the outputs. It is possible for a programmer to make a mistake in the program, but no mistake will halt the operation of the PLC; it keeps on running. Because it cannot freeze, it performs reliably throughout its long life, requiring little if any maintenance.
In comparison, the average PC computer is built with commercial components that last only a few years. It needs a controlled, cool, dry, clean environment and has little tolerance for the dust and electrical noise caused by the motor starters and valves found in industrial plants. Unskilled personnel can easily corrupt the Windows system and it requires frequent attention. In addition, the frequent Windows updates can shut your plant down at a critical time. BatchTron uses a PLC and is free from all these issues, making it extremely reliable as a result. The data collecting and management tasks, however, can be done on a PC computer in an office environment. If the computer breaks down, the batching system can continue unaided for as long as necessary.
BatchTron’s extreme reliability reduces your maintenance cost by a factor of 10 or more.
Usually yes, occasionally no. When you give us the details for the plant, we set-up the BatchTron for it by making many menu choices. Occasionally we have to add a custom function if it does not exist in the setup menus. The degree of customization depends on the plant. If it is a simple plant like a “dry mix” ready-mix plant, the BatchTron configuration is standard and it can be used on many other similar plants. If it is a more complex precast plant with two or more delivery stations, the answer is most likely “No, not as it is”.
We can always modify the software to suit your application, however. Since BatchTron has no hard-wired panel controls, you can update PLC and screen software on-line to suit any plant configuration. If you do this after the system has been built, however, a reprogramming charge will apply. The cost will reflect the complexity of the change.
We routinely update customers’ software to accommodate plant changes and additions. For small changes we do this on-line. Large changes occasionally require a plant visit to start up and train operators while we make modifications to suit individual preferences. We offer a very personal service and try to accommodate your wishes at all times.
BatchTron is sometimes customized, but can always be changed to suit any plant.
This depends on your present batching method. If you are now using a skilled manual operator, he can probably equal the speed of BatchTron when in top form. Manual operators tend to be erratic, however, and they call in sick now and again. BatchTron is consistent, giving you the ultimate in speed, plus the accuracy that you require, 24-7. And your skilled operator can get on with other things that need his skill, employing him in a more effective manner.
If you already have basic automation, BatchTron can usually improve both speed and accuracy. Systems older than 10 years rarely have self-tuning and automatic moisture compensation. Consequently, regular adjustment is necessary to achieve the best performance. PC computers are not “real-time” systems. They run at a speed determined by the background “overhead” processes of Windows which varies all the time. Add to this the updates that shut the system down from time to time and you will see major benefits from BatchTron.
BatchTron’s speed, accuracy and reliability will impress you.
Of course, but you need the electrical knowledge to wire everything from the electrical schematic. Also, you must connect the load cells on the scales via shielded cables and calibrate the scales with test weights. You can use a local scale company to do your calibration and a competent plant electrician to do the wiring. If you have the necessary skills at hand, you probably don’t need our help.
Many customers and dealers have self-installed BatchTron controllers with no problems, and they have saved on the cost of installation. If you find that it is too much, you can always call us to finish the job. Most customers prefer us to be present, however, even if they do most of the work. This is a good safeguard against possible damage or delays and we can train your operators at the same time.
If you have the skills, go ahead. We’ll help if you get stuck.
The BatchTron screen duplicates most of the manual panel’s functions and you can use either one with no ill effects. You can connect feed gate and scale discharge controls in parallel to give manual backups of these functions. This is especially useful if scale dials or indicators are retained. You can fit electronic scale indicators with connectors to allow quick change when required. The only problems occur with dual-solenoid valve controls such as fitted on most mixer discharge doors. These need an isolating switch to prevent both the BatchTron and the manual control from trying to act at the same time. If both the “open” and “close” valves are open at the same time, the result is unpredictable.
Also, you can create a safety hazard when the mixer is started from an external switch if it is not fitted with a physical time delay relay and warning horn in the MCC; BatchTron incorporates these functions in its software. It is impossible to start the mixer from BatchTron without sounding the horn, as required by OSHA and other regulatory agencies.
Manual controls can be used, but check the important exceptions.
You can enter moisture values from BatchTron’s moisture screen or use remote sensors such as our AquaSense 2280D moisture sensor in automatic mode. The moisture in the aggregate makes up some of its weight. Because of this, the actual batched weight of dry aggregate is less than the desired target. BatchTron calculates this error and compensates for it, based on the moisture value. The result is new aggregate targets which are higher than the dry targets in the formula, in proportion to the moisture.
Likewise, BatchTron calculates the water contained in all the aggregates and subtracts it from the water target. This gives a new target which is less than the formula value. The result is better consistency from batch to batch and day to day because every batch conforms to the theoretical mix design. The only errors are caused by the normal batched weight variances and, of course, errors in any moisture values entered by hand.
You cannot meet the accuracy requirements of most concrete associations without automatic moisture compensation (from sensors) on sand and other fine aggregates.
Other batching frequently asked questions – contact us directly for an answer.