|
Digital scales are commonly used in many packaging processes. They may be involved in an automatic filling line, where containers move into place on top of a scale platform. Some sort of filling device is controlled by the scale. This may be an augur for filling a powdered material, or a valve for filling fluids, or a conveyor line for other types of products. When the desired amount of material has been placed into the container, the scale can shut off the filling mechanism until the next container is properly positioned.
Monitoring the weight of material in a cylinder, tank or tote is yet another area where electronic scales are employed. A cylinder scale, floor scale or platform scale can measure how much liquid remains. Target weights may be set to warn when the remaining material is below a desired level, or when it has been completely depleted.
Often, the weight information is required directly at the location of the scale. In a shipping or receiving department, the scale operator may need to know this data in real time. In the case of monitoring levels within a container, the people at the scale may be required to re-fill or change the container. But there are also many situations where the weight data is required at a different location. It may be that this information must simply be recorded for future use. Or, for example, outgoing package weight information may need to be processed onto a shipping manifold. This same weight recording may need to be entered into the accounting software so that the customer may be correctly billed for the shipping costs.
Of course, a human operator could simply record the weight information on paper, and store or use these weights elsewhere. Usually, it is preferable for the industrial scale to electronically transmit the data to the required location and application.
Many digital bench scales, platform scales and parts counting scales have offered an electronic communication connection called RS-232. A wire can transmit the scale data, in serial format, to a device that can accept an RS-232 input. This may be a computer terminal, or a printer, a programmable logic controller, or some other device. While RS-232 has been used for many years, it has a number of disadvantages. Typically, a separate wire has to be used for each scale. The overall distance between the scale and its target device is quite limited. Furthermore, many newer computers no longer come equipped with an RS-232 input.
Virtually all newer computers are now provided with a number of Universal Serial Bus (USB) connections. Floor scales, precision scales, cylinder scales and most other digital scales provided by some of the leading industrial scale manufacturers are now also available with USB output devices. This allows connections to be easy and simple to implement. But the maximum USB distance is even shorter than that allowed by RS-232. Also, separate USB wires are still needed to collect the scale data when there is more than one scale producing this data.
A superior data transmission protocol is the widely used Ethernet standard. Those industrial scales that are equipped with this standard may be directly connected into a Local Area Network (LAN). Many industrial facilities already provide this LAN for general purposes of connecting all of the computers. Ethernet hubs may be used to allow multiple electronic scales to communicate over the same cable system without requiring long wire runs to a central point. Communication distances may be increased to virtually anything needed using industry standard repeaters, network extenders and other devices. With the proper software system, the LAN may also be connected to the Internet. This provides access to the weighing scales from anywhere in the world who has been allowed access into the software application. This may be particularly useful for companies who have many different locations.
|
