In fact, you weren’t even sure how to back it up anymore. If it’s only happened once in your life, it was one time too many—right?
Memory keeps getting cheaper and smaller. Just think of the number of pictures from your digital camera you can store on one small “card” that slides into a small slot. Computers use something called “EEPROM” or electrically erasable programmable read only memory. A class of memory called “flash” was developed and showed much promise. Compact Flash memory (CF) was thought to be small and inexpensive, but then came secure digital (SD)—faster, smaller, cheaper. Even that wasn’t good enough, so now there is mini-SD and micro-SD.
Not surprisingly, automation control suppliers love to leverage these popular computing technologies whenever possible. And the problem extends beyond just the application program in the controller, explains Fabio Malaspina, a product manager for controls vendor Rockwell Automation Inc., in Milwaukee. “Up until now, programmers just saved a copy of the application into controller memory with flash memory built in,” says Malaspina. “We’ve now added removable compact flash. This will evolve as new products enter the market. Customers can use this to load a program revision or even move the program via the flash card to a replacement controller to get the process back up and running quickly.”
Spiraling complexity
Problems grow quickly in larger systems with many intelligent devices. “In a large system with many components, the system is configured to the firmware revision level of all the intelligent devices,” says Malaspina. “Let’s say there is a problem with a system late at night. The technician needs to go to stockroom, get a replacement module, check firmware level, update, load and install. And that’s if he can find the firmware revision and find what it should be to match the system—quickly of course. The problem is how to make this simpler.”
So Rockwell added a feature to its controller called Firmware Supervisor. It saves the application code plus firmware levels for all of the modules in the system. Any time a module is replaced, the controller knows what the firmware level is supposed to be. It checks the new module’s firmware. If it matches the expected level, then all is OK and the controller can start. If not, then it can flash the correct code to the module firmware. “OEMs (original equipment manufacturers) can use the feature to save a lot of expense in commissioning machines,” says Malaspina.
The situation in automation is not limited to controllers. Product Manager Rami Al-Ashqar, at automation vendor Bosch Rexroth Corp., in Hoffman Estates, Ill., says a variety of automation components need ways to quickly load a backup configuration or program in order to keep production moving. “Our System Mate gives the ability for automation components to be powered down and quickly replaced using a personality module swap. This is done without a personal computer, but in various ways for each component. Motors have an EEPROM. Integrated motor/drive combinations and drives are designed for SD card memory. Controllers and human-machine interfaces use compact flash. In the previous technologies of the ’80s and ’90s, drives were configured to a motor through tuning resistors. Now with CF and SD cards, you can take out an old one and put in new, then load the configuration settings. It’s all about serviceability. Sometimes, people just make too many changes to try to get the machine from 95 percent to a higher efficiency. Then it stops working. With the flash drive, they can go back to the original to get running again.”
Gary Mintchell, [email protected], is Automation World’s Editor in Chief.
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