Interconnect Your Scales Into One Computer System

By Author: John Tang
Total Articles: 507
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Industrial scales are designed to measure and display the weight of anything put on the platform. The electronic scale user can read the weight on the digital indicator. The indicator is designed to offer the user a clear and accurate reading. Generally, a numeric or graphics display allows the user to select the type of units, such as pounds or kilograms, and enter a tare weight, so that either the net or gross weights may be shown. If the user wishes to record or store this information, they would need to manually record the data. Alternatively, many digital scales offer printer output connections, so that the data could be printed and the records retained.

Arlyn Scales has developed software that allows data to be collected from one or more scales, and forwards the data into a computer system. The scales may be of any of a wide variety of types, such as bench scales, platform scales, parts counting scales, drum scales, floor scales and a variety of others. Up to ten different scales may be wired together and then connected into the computer. A special Windows based program, Remote Indicator, runs on the computer.

Generally, ...
... the printer ports available on scales are RS-232 standard communication ports. This type of circuit only supports a single device. This would require additional RS-232 ports on the computer, and a separate cable for each scale that is connected.

A superior type of communication port, RS-485, is used by Arlyn Scales. It is similar to RS-232, but allows multiple scales to be connected to a single cable. This cable can daisy chain between each scale, and then run to the computer. At the computer, Arlyn provides a special RS-485 to Universal Serial Bus (USB) adaptor device. This adaptor reads the data from each scale and converts it into standard USB format. Virtually all modern personal computers provide ports to allow USB devices to be connected. This system is inexpensive and very easy to implement.

Once the data is available to the computer, software must be provided to read this data and compile it in usable form. The software may also be used to control the scales that are connected. Arlyn Scales provides free Remote Indicator Software. This is a Windows based software application that allows the user to display the real time weight display of up to ten different scales at the same time. The weight shown on the computer monitor will be a copy of the weight that is shown on the digital indicator that is attached to each scale.

The Remote Indicator Software also allows the data from each scale to be written into an Access Database table or an Excel spreadsheet. It is also possible for the computer to note the time that each record was written. This provides an excellent means of remotely monitoring weight on the scale platforms. The user may also use this data to provide their own charts and graphs.

In certain situations, users of industrial scales would like to insert weight data from the scale directly into their own application. These applications may be in-house software that is associated with their production facility, or may need to be attached to their accounting software. In some cases, there may be inventory control software involved. For these purposes, Arlyn Scales provides a free Send Keys utility. This software will send scale data into the field that is currently active, or has the focus, in any Windows based program. It is the equivalent of the user manually typing the data into that field, but instead, the software utility will perform that function.

The Send Keys utility can also be useful if the scale user wishes to write their own software utilities, using Visual Basic or similar programs. These programs could be used to control peripheral hardware, such as feeders or fillers. The custom program could control hardware outputs from the computer that are passed through relays. These outputs may now turn on or off a wide variety of switches, valves, solenoids or pumps. The weight that is read in from the scale platform will then be the controlling parameter. The software could also be part of a feedback control loop, where the devices could be feeding material onto the industrial scale platform. Now the flow rate, or speed of dispensing may be controlled.