DELTA SPECIALIST HELPS MAJOR REGIONAL DISTRIBUTION CENTER OUT OF A JAM

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1 Automation Service News from DELTA AUTOMATION, INC. Your production is our motivation DELTA SPECIALIST HELPS MAJOR REGIONAL DISTRIBUTION CENTER OUT OF A JAM His extensive programming experience makes the difference We ve recently had the opportunity to be of assistance to a large area warehousing and distribution center, helping them to integrate PLCs, programs, and other components of their conveyor systems. Originally asked to help them to upgrade from one Allen Bradley platform to a newer one with Ethernet functionality, including installation of the new PLC and the downloading of the existing program to it, our Allen Bradley integration and programming specialist, Ed McClure, saw the project become more involved than expected when the new PLC encountered a problem running the existing program. In discussions with THE CIRCUIT BY BOB CULLEY PRESIDENT DELTA AUTOMATION, INC the manufacturer, it became apparent that they had never experienced that particular problem. An otherwise inconsequential difference between the old platform and the newer one could, in this relatively unique situation without a great deal of experience and some creativity possibly be a deal breaker. Fortunately, the distribution center had chosen exactly the right man for the job, and it didn t take long before the problem was solved and the conveyors were running just the way the customer intended. Ed was also asked by our new client to troubleshoot a problem they were experiencing in a second warehouse with a conveyor system. A pop-up gate which, as the name would indicate, was designed to force a barrier to rise up at various programmed intervals to stop the progress of products moving on the conveyor line, was periodically malfunctioning, causing traffic jams in the product flow which frequently resulted in items being pushed off the conveyor onto the floor. The client was very dissatisfied with the performance of the distributor who had sold them the system, convinced that the distributor s response to the problem had been perfunctory at best, and that they had overcharged for services which had done nothing to solve the problem. The resulting thorough evaluation of the system and its setup soon made it clear that the cause of the problem lay in the programming done by the distributor. With his extensive experience in highly structured programming, Ed was able to quickly correct the problem and get the conveyor system working in the way our client had originally intended. Ed continues to work with this client to improve their efficiency in moving products into their warehouses and then onto trucks that distribute them to the many stores in their extensive chain. It s a cliché, but time definitely is money, and this is just one of many examples where the experience, knowledge, and creativity of Delta employees have proven invaluable to our clients. 2 INSIDE Tech Tip: Synchronizing PLCs 3 Updating a lumber mill: New WEG drive and motor Bright idea: 4 New WEG pushbuttons 5 Contact: Delta sales, service and support

2 2 TECH TIP: SYNCHRONIZING EVENTS BETWEEN PLCS AND COMPUTERS The Task Develop ladder logic to synchronize barcode and routing information generated real-time in a PLC with a PC that is connected asynchronously, via Ethernet, to the PLC. In this example the barcode reader sends a 10-character ASCII string to the PLC (the product type and destination are encoded in the barcode) each time a package passes under the reader. BARCODE READER DISTRIBUTION SYSTEM PLC COLLECTION PC The Solution 1. Given the asynchronous nature of the communication between the Data Collection PC and the PLC, the PLC must buffer barcode data from each package in real-time, then pass the buffered data to the PC when the PC is ready to accept it. Create two ASCII files of 100 words each as shown in the graphic below. One will be used as a stack to enter the barcode data from each package as it is read, the other is used as a copy buffer for the PC. now read the next buffer full of barcode data and the PLC can go back to store live data in its LIVE STACK. Data synchronizing logic similar to that shown above is always necessary when a PC communicating with a PLC needs to gather event-based data from a PLC which occurs asynchronously to the PC. LIVE STACK PC BUFFER 2. Write an algorithm to implement the transfer of data between PC and PLC as follows: Initialize an integer pointer to point to the first word in the LIVE STACK (A25). A25:100 A25:99 A25:98 A25:97 A25:96 PACKAGE 20 A26:100 A26:99 A26:98 A26:97 A26:96 When the first barcode is received from the reader by the PLC use a COP instruction to copy the barcode into A25:[pointer]. This will put the barcode data into A25:1-5 (5 words = 10 ASCII characters). Increment the pointer by 5 to point to the address to in the stack to receive the next barcode (A25:6). Continue to read, copy, and increment pointer, as each new barcode is read. A25:10 A25:9 A25:8 A25:7 A25:6 PACKAGE 2 A26:10 A26:9 A26:8 A26:7 A26:6 Define a PC READY bit that the PC will set in the PLC datatable when it is ready to read barcode data. When this bit is true perform a copy of A25 to A26 for 100 words, use an FLL instruction to clear the contents of A25, reset the pointer to 0, and clear the PC READY bit. The PC can A25:5 A25:4 A25:3 A25:2 A25:1 PACKAGE 1 A26:5 A26:4 A26:3 A26:2 A26:1

3 Updating a lumber mill 3 Replacing hydraulics with raw horsepower yields a more flexible operation Recently, Delta was asked to assist in the application of replacing a hydraulic motor that runs a conveyor chain that moves rough cut lumber to a final sizing saw. The hydraulic motor system had been in use for some time and was troublesome for both the operators and the maintenance crew. The operators need to change the feed speed occasionally, but that is next to impossible with the hydraulic system. The maintenance crew had to deal with fluid leaks that sometimes got onto the lumber and ruined it. The solution was to install a WEG 100 hp drive and WEG motor to replace the New workhorse in the mill hydraulic motor. The drive and motor were pre-programmed here at Delta s facility to reduce the installation time on site. Also a temporary wiring set up with a start/stop and speed pot was provided to allow the installation crew to perform small moves (jogs) to the motor during the installation to facilitate the job. In addition to being more reliable and user friendly, the advanced diagnostics capabilities of the WEG drive will now allow the operators to limit the power and torque applied to the chain to prevent damage to the machine when a jam occurs. In the past, a jam could mean expensive damage and downtime if the system was not shutdown quickly. The payback on this system will be complete when the first jam occurs and the machine is not damaged. WEG variable frequency drives are being successfully installed in many new applications where no drives were previously in use. Contact Delta if you have an application where you think that a variable frequency drive may be of benefit to your process. FLEXIBILITY. The advanced diagnostics capabilities of the WEG drive allows the operators to limit the power and torque applied to the chain to prevent damage to the machine when jams occur.

4 4 BRIGHT IDEA WEG pushbuttons offer the brightest pilot lamps in the industry WEG has developed, and Delta Automation, Inc. is proud to stock and distribute, a complete new line of robust, modern, and versatile pushbuttons, pilot lamps and controls. These devices have a patented mounting and locking mechanism for the contact blocks to attach to the operator itself. This mechanism allows a no tools approach to the assembly and disassembly of the unit. In the fabrication of panels and control boards, the amount of assembly time is reduced significantly. During the maintenance or troubleshooting of a machine or panel, the accessibility to the contacts makes the task much easier and less time consuming. These devices are constructed using high impact polymers. Impervious to oils and other contaminates which can corrode metal units. The LED pilot lamps are the brightest in the industry. This is accomplished by using the highest quality LEDs in conjunction with color coordinated mounts and lenses. These lamps are even visible in sunlight. They are ideal for outdoor panels and displays. Please contact Delta for a demonstration of these new and innovative design pushbuttons and controls. UPDATED CONTROLS. Using all standard-issue, off-the-shelf components, this new bypass panel works within existing systems footprint and offers some enhancements. Bypass panel constructed for aging HVAC system A national pharmaceutical company with a large number of aging HVAC systems using variable frequency drives was interested in updating their systems. These systems were originally custom built to meet their specifications. The problem with custom-built products is that you are then locked into that manufacturer for any parts or service. Their contractor approached Delta to help seek a solution to replacing these custom drive systems. The most practical and cost effective solution was to utilize off-the-shelf components to fabricate a panel which would fit within the existing systems footprint which duplicated its function with some enhancements. Delta chose to use all WEG electrical components and a WEG variable frequency drive. The WEG components are all regularly stocked parts. This allows the end user to service and maintain the system utilizing their maintenance crew. Once the end user approved the layout, design and components. The panel was constructed and shipped to the contractor. The contractor waited for a planned shutdown time and replaced the old panel with the new one. The system worked as planned. In addition to having a two-year new product warranty, the end user has the comfort of knowing that the parts used are all standard issue. If you have panel building/fabrication needs, contact Delta Automation, Inc. THE NEW PANEL. Ready for delivery.

5 CONTACTS 5 Delta Automation, Inc Charles City Road Richmond, VA tel fax Toll free PC-DELTA ( ) AFTER HOURS Emergency Service or Parts Call our main number or digital pager EXTENSION 5 5 Leave a message and someone will respond within fifteen minutes! Bob Culley President Margarete Culley Vice President/CEO Roy Caudle Service Bernie Wieland Sales Clark Jones Sales Vann Barden Outside Sales Mike Martinelli Repair Dawn Pratt Accounting bobculley@deltaautomation.com mculley@deltaautomation.com roycaudle@deltaautomation.com berniewieland@deltaautomation.com clarkjones@deltaautomation.com vannbarden@deltaautomation.com marti@deltaautomation.com dawn@deltaautomation.com DELTA is published quarterly by Delta Automation, Inc. at 2704 Charles City Road Richmond, VA To subscribe, call PC-DELTA 2007 Delta Automation, Inc. All rights reserved