During the recent ISWM conference, dealers were asked about connectivity in the weighing industry. The consensus was that connectivity is both a problem solver AND a black hole of support – efforts go in and little comes out. Yet in other industries, new connectivity technologies are providing valuable
1) RS232 is dead, right? – It’s all USB now
Why would someone say RS232 is dead when more weighing instruments in the market today are equipped for RS232, not USB? It’s probably because RS232 is no longer provided on computers using the Windows® operating system. RS232 ports and HyperTerminal® software were removed. While RS232 is now a niche market for computers, it is still very relevant for the weighing industry. Many installers prefer RS232 over USB since it is simpler to diagnose problems, often more robust and supports legacy equipment. Other industries that deal with high dollar capital equipment have an easier time with the move from RS232 to USB. It is a bigger issue for us since connectivity support issues are similar for a $1000 balance or a $50,000 process system. 50X more revenue per port helps smooth out the support wrinkles and costs.
But RS232 can be added to computers as boards or port adapters, and free HyperTerminal alternatives can be downloaded. This was not always the case and there were notable market stumbles along the way, especially with RS232 to USB adapters. You don’t need to abandon RS232 connectivity because the computer you just bought was not supplied with RS232 out of box. Dealers and end-users just need to be pointed in the right direction. This article will provide a few hints and short cuts for providing end–user RS232 support in the USB age. This may help you boost your image and distinguish your company as a value-added dealer supporting industry solutions - even “legacy” RS232 solutions.
2) Advantages and Issues with USB
If you have USB – use it. For most user cases USB is better, easier to set up, and new computers have plenty of USB ports. But you do need the correct USB driver and you MUST install it correctly to have the benefits of USB simplicity. Since USB means forgetting about RS232 baud rates, data bits, stop bit, and flow control, USB driver issues are a small price to pay. Right? Well, maybe…
Be prepared to manage a few issues with USB in commercial use, 1) USB connectors are not secure and may be pulled out by accident, and 2) USB connectivity problems, though less frequent than RS232, are often harder to solve. The USB connector issue can be solved with Velcro, duct tape and cable ties - inelegant but effective. Unfortunately, fixing the USB driver problems does not have a simple workaround and in fact may become a serious support issue best resolved by remote expert access to the computer and expert reconfiguration. Do you have someone in your organization who understands USB driver install problems?
The overall goal for USB was to simplify the driver install process for typical users, not the niche end-users we have in our industry. In achieving this goal, Microsoft® needed to make engineering and functional choices and included some business choices beneficial to Microsoft and the computer industry but not in the best interest of niche connectivity for laboratory and industrial market users.
So if the USB driver install works correctly first time – Great! It is due to all the hard work put into engineering and documentation by the manufacturer or distributor and the careful attention by the end-user to USB driver install instructions. But if not, read on….
3) How to avoid the dark side of USB Connectivity
The dark side of USB connectivity is not widely known and certainly not well understood outside the engineering and support teams of USB equipment developers. If the USB driver install fails for ANY reason – it may not be simple to correct. Period.
USB driver install problems are serious for a number of reasons; 1) Windows USB Plug and Play is a highly engineered and cryptic system, 2) most support staff in many industries do not understand it well enough to effectively diagnose and may need to elevate the support request, and 3) the escalation support staff still often needs development engineering support. Why are USB driver issues so complicated?
Unfortunately an explanation of why the USB driver issues exist requires a deep and complicated understanding of how USB drivers are supposed to work in the Windows operating system - and the resolution may be out of your hands. What you do need to know is - if the first USB driver install fails - you are now treading on thin ice. Your next step could determine if you have an easy or very difficult fix. Slow down and tread carefully.
Unfortunately all USB drivers are not created equal or perfect. If the USB driver or install process is flawed from the manufacturer then everyone downstream to the end-user will suffer. I have personally experienced that from an $800M global company. Got lots of “We’re very sorry!”, and, “It will be fixed in the new driver revision”, but in the end I needed high level engineering support to resolve the issue. And I needed to personally re-write the end-user documentation to 1) increase chance of success on first try and 2) provide clear uninstall procedures – if the end-user wasn’t being careful at first install attempt. Better in-house testing and documentation by the manufacturer could have avoided the entire problem completely.
Even a perfect USB driver must be installed correctly to get it right on the first try. The manufacturer needs to provide clear and complete instructions for this process. And the end-user needs to follow these instructions exactly for the target version of the Windows operating system – the instructions and order of steps may be different for different versions.
Unless managed correctly, USB has a higher reward level but can also be higher risk from a support point of view. The risk of USB can, and must, be managed by careful documentation, training and strong caution to the end-users to follow the instructions exactly.
USB is a great technology which allows easy connectivity for devices in retail mass markets on Windows computers. We should encourage its wider use in our industry – but with eyes open.
4) One Connectivity advantage of RS232 over USB
There is one clear advantage to RS232 over USB but it only applies to cases where longer cable length is needed. USB is limited to 5 meters unless extended with powered repeater devices. RS232 does well up to 15 meters with lower cost cables and may work up 100 meters with high quality cables.
There are a wide variety of companies that offer wired, wireless, fiber optic, TCP/IP and telecom extenders for RS232, which may be connected inline for an effective distance of 10,000 feet or more, or globally via telecom or the internet. There is not yet this broad variety of USB extenders and probably will never be for technical and market reasons.
5) All RS232 to USB adapters are NOT created equal
If you do need to equip a USB computer for RS232, you must understand all RS232 to USB adapters are not created equal. Unless your manufacturer or distributor tells you otherwise – use only the exact RS232 to USB adapter supplied or recommended by the manufacturer. The RS232 to USB adapter is a highly engineered converter in a small package that is deceptively simple. Higher cost RS232 to USB adapters are not necessarily better. What is important is that you use the exact adapter your manufacturer has used in their testing, and supplies for use with the product.
Some commercial software also provides robust connectivity solutions for enterprise deployment based on DDE exchange protocols or serial data streaming over TCP/IP networks. The serial hardware devices that support TCP/IP are called serial servers. This is a very powerful and well accepted method by IT professionals, to provide network connectivity for legacy RS232 devices in industrial environments. If you need this, be sure your wedge software supports it – not all do.
Once you succeed in getting your weighing data to Excel - a skilled Excel Macro or Visual Basic® programmer can develop complex applications that utilize the weighing data and provide fully integrated software solutions without the high cost and extended time frame of a stand-alone dedicated software application.
Supporting RS232 connectivity will still be relevant as long as RS232 is provided with scales and balances. This should be the case for years to come. RS232 to USB adapters and HyperTerminal alternatives can restore full RS232 connectivity to a USB only computer for under $50. With the help of manufacturers, value added distributors and careful dealer efforts to avoid the known pitfalls and develop the skills to utilize the known workarounds – reasonable value added dealer support can be provided for both USB and RS232 connectivity. As long as your efforts are based on known validated solutions, your support efforts can be cost effective and avoid the black hole of connectivity despair.
With a nod to Monty Python, RS233 is not dead yet, in fact it’s looking better.
Microsoft, Windows, Excel, and Visual Basic are registered trademarks of Microsoft Corporation in the United States and other countries. HyperTerminal is a registered trademark of Hilgrave, Inc.
References: For more details on the connectivity solutions mentioned in this article including references discussed please send an email including “Connectivity” in subject line to firstname.lastname@example.org.
About the Author
Rich Puestow is a recent addition to Intelligent Weighing Technology team with responsibilities for channel expansion and connectivity development. Rich is an analytical chemist with experience in test and research labs for government, research and industry. His connectivity background includes integration engineering to support serial, fiber optic, wireless, and network connectivity for gas sensor safety systems added to chemical plants and refineries worldwide.
Intelligent Weighing Technology, Inc. is a wholesale distributor and value added integrator for weighing products and components, located in Camarillo, CA. The company founders and co-owners Richard Sharpe and Paula Sharpe have an extensive background in the weighing industry for products and components. Intelligent Weighting Technology provides additional services and support to the dealer network beyond the manufacturer; offerings such as extended connectivity support.