To thrive—indeed, to survive—in today’s increasingly competitive global marketplace, manufacturers must leverage cutting-edge technology and operate at high levels of efficiency. Burr Oak Tool Inc. (Burr Oak), a designer of custom production machinery for the world’s heating, refrigeration, and air conditioning industries, is no exception. So when management at the Sturgis, Mich.-based OEM made plans to develop a new, cost-effective product it hoped would open the door to overseas markets, they knew they would have to make some changes to their usual way of doing things.
Burr Oak is known for rugged, high-quality products that provide consistent, dependable results for users. For more than 65 years, the company has installed heat transfer and tube processing equipment worldwide. “At this point, we wanted to build a high-quality fin press for the HVAC industry at a more economical price,” says Eric Lund, controls and software engineering manager at Burr Oak. The objective: targeting new customers in overseas markets such as Asia.
For the tools and capabilities needed for the new press, Burr Oak turned to Siemens Industry. Siemens’ new line of S7-1500 programmable logic controllers and proven engineering software, TIA Portal, were ideal for the initiative. Burr Oak was long familiar with Siemens technology, reputation, and global presence, having worked with the company for more than a decade. “Coincidentally, as we were developing our new machine (the FP 400), Siemens approached us about the new PLC and the latest version (V12) of TIA Portal,” says Lund. “The preliminary performance and pricing value on the PLC was especially attractive, as was its integration with TIA Portal. They seemed like a perfect fit for the new press with their outstanding processor performance and a price that would help us achieve our goal of producing a lower cost machine.”
Simplifying Task Management
Burr Oak discovered significant advantages in the hardware and software to benefit its new launch. On the software side, it was already using an earlier version of Siemens’ TIA Portal, integrated automation software that combines PLC, PC-based control, HMI, and network configuration in a single engineering environment. While the company was familiar with some aspects of the software, by probing more deeply into its capabilities, the staff found a number of features especially valuable to the development of the new fin press:
- Trace functions
- High-level programming
- Cross reference features
- Project organization
A dynamic graphical editor that illustrates changing variables handles the trace functions for real-time diagnostics. “It’s like having an oscilloscope so I can see the values of analog signals, maybe the position or voltage of a motor,” explains Lund. “At the same time, I can overlay that with the state change of binary values and improve our timing, which is very important to us.”
Using the trace feature, the company’s engineers can put the logic they have written through its paces and verify its performance. “The FP 400 fin press shows the position of the ram on the press,” notes Adam Broadwater, research and design engineer at Burr Oak. “When we trace that encoder position with the machine running, we can pull in binary operations (e.g., switches, valves) while the press is rotating and verify that operations are turning on and off properly during the rotation of the press.”
Burr Oak uses an expensive progressive die in its machines, so it is critical to protect these components as the tooling shifts in and out. Timing is critical. “Shifting the tooling at the wrong spot could ruin it,” says Lund. Having data that shows the position of the ram and when the tooling is coming in and out allows assurance that the operation occurs in a safe position. “TIA Portal and the tracing feature in particular is a powerful validation tool that helps us do this,” explains Lund. “It validates that the software we’ve written is functioning as expected and helps protect the die by adjusting the timing precisely.”
Burr Oak also found TIA Portal’s high-level programming languages a significant benefit. The engineering software includes five IEC programming languages: ladder logic, function block diagram, statement list, a graphic programming editor for sequential steps, and SCL (structured control language), a high-level scripting language editor. According to Broadwater, the new SCL editor in V12 of TIA Portal makes is very fast to write software—to condense blocks so code can be shrunk to better see what is going on, to automatically populate variable names, to create a library for a function and then use it in a different project.
TIA Portal’s cross-reference feature lowers the temptation to look for any other code editor. Cross referencing, which enables common handling across all the IEC programming languages, lets the user browse for tags in all blocks of the PLC and, importantly, in any of the HMIs connected to a PLC that reference that tag.
The file tree in TIA Portal makes project organization remarkably simple. “It has features I wasn’t accustomed to; but, after I started using them, I grew to like them a lot,” says Broadwater. Multiple pieces of equipment are being controlled within the PLC. “With the file tree, I can sort my function blocks and data blocks into a logical folder structure,” explains Broadwater. “That was not available in other editors. This allows me to condense my project so that when I’m working on something inside it, I don’t have to have all the other function blocks showing in the project tree.”
Hardware Benefits, Some Unexpected
On the hardware side, Burr Oak found the features of Siemens S7-1500 Series highly advantageous, from improved I/O modules and wiring techniques to the diagnostic display on the front of the unit. The innovative controller maximizes productivity for machines and installations that place high demands on speed and deterministics. The seamless integration with TIA Portal also adds efficiency and usability.
“The display was apparently intended for diagnosing wiring faults, but we discovered an unexpected application,” says Lund. “We’ve been striving to write software with a core code applicable to each machine, so that we are not constantly writing unique code.” A core code runs the base machine, but each customized unit has different in-feed and out-feed options. “So we created function blocks to operate each type of mechanism with some commonality amongst them,” he explains. “We can mix and match the options with the core code and not have to constantly debug and reproof all the code as we customize the units.”
When a new machine is commissioned, the code already has been debugged. A technician needs only to install the programmed memory card, start up the controls, enable/disable the in-feed and out-feed options, and debug the machine itself. “For years, the software engineer loaded the software on memory cards and passed the machine to a technician for start-up,” explains Broadwater. The technician then set the options. Invariably, at this point an error occurred in the PLC program. Typically the problem was a wiring or plumbing mistake, not an error in the software. “Nonetheless, a software engineer needed to unplug from his desk, reset up on the shop floor, connect to the machine, then help find the error. Now, with the display screen and diagnostics capabilities of the S7-1500 PLC, the technician can use the interface to go into the PLC and see what errors are there. By referencing the machine schematics, he can determine what is wrong without involving a software engineer.”
So creative use of the display has made commissioning faster and simpler. Full diagnostic information is available and no PC is needed. With simple training, Burr Oak technicians now can solve most problems and complete the commissioning themselves while the software engineers remain at their desks, using their skills and time more efficiently, saving the company time and labor costs.
Other advantages of the new hardware include:
- Need for minimum inventory. The S7-1500 uses a standard terminal module across all I/O modules.
- Simple wiring procedures. With the wiring location on the front of the unit, a technician can simply pull the terminal module out of the I/O position so it is not physically connected to the PLC.
The Bottom Line: A Powerful Combination
Lund and Broadwater agree that the Siemens products have delivered significant benefits to Burr Oak operations. “Together they have reduced engineering time some 30 percent,” says Broadwater. “We weren’t holding a stopwatch to our activities, but everything moves faster with TIA Portal. Also, commissioning the machines in the I/O modules is saving significant time. We make between 50 and 75 fin presses annually. In the past, it took at least two hours of software engineering time per machine to debug errors. Now those hours are saved, because the technicians can debug the units themselves.”
Lund concurs completely. “This has been a very positive experience for us,” he says. “The PLC expedites debugging. The display dramatically cuts the time software engineers spend on the floor doing routine tasks. At a recent sales meeting, we told our reps about the new machine and one of them was so happy with what we’d done with its design and layout that he said it appeared we had made the machine specifically for his customer base in India.”
The objective: targeting new customers in overseas markets such as Asia objective achieved.Have an Inquiry for Siemens about this article? Click Here >>