PLC systems are typically highly complex, as they integrate numerous board modules required by current-gen automated industrial environments, including:
- Programmable logic controllers (PLC) or programmable automated controllers (PAC)
- Distributed Control Systems
- Digital and analog IO-modules
- Field bus communication modules
- Industrial Ethernet interfaces
- Wireless communication module
“Clearly, the diversity of board designs for industrial PLC applications is challenging for R&D departments. For optimal hardware and software development, designers require a broad, efficient product family where development can be re-used as much as possible,” an Atmel engineering rep told Bits & Pieces.
Indeed, for main CPU applications, Atmel’s SAM9 series offers up to 400Mhz ARM926EJ core with up to 32KB instruction and data caches for fast execution times, while a unique dual EBI (External Bus interface) feature allows connecting dedicated circuits for field bus or real time industrial Ethernet communication without strongly impacting the bus load and the performance of the application.
“In addition, the implementation of the TCM (Tightly Coupled Memory) interface on selected products enables access to the internal SRAM with zero wait state at 400MHz. With this feature, time-critical code sections and interrupt routines can be executed fast and deterministically,” the Atmel engineering rep continued. “Plus, our microcontrollers support up to 37 DMA channels with double buffering feature to minimize CPU load and reduce real time constraints, while support for DDR2 external memory enables lower cost and longer availability for CPU devices.”
Additional key features? An integrated power-on-reset (eliminates the need for cost-intensive external power management IC), serial NVM for system boot (allows smaller PCB layout), industrial BGA package with 0.8mm pitch (eases PCB layout and reduces assembly costs) and system security solutions (peripheral components).
“In terms of I/O module solutions, Atmel offers high-speed serial peripherals for a fast communication with backplane bus interface or the connection to high resolution external ADC or DAC, with SPI data rates up to 48Mbps on the SAM3U. CAN modules are available on Atmel AVR UC3, megaAVR and AT91SAM microcontrollers,” the engineering rep explained.
“There are also numerous 16-bit timers with input capture function for time stamping, PWM channels support control and dim functions for LEDs. Of course, Atmel supports a rich set of analog functions such as 12-bit ADC and DAC, as well as analog comparator for monitoring the operation condition of the IO-module. And last, but certainly not least, we offer a high performance CPU up to 96MHz with integrated MAC unit supporting the growing demand for signal conditioning on the analog IO-module.”
Interested in learning more about designing PLC and I/O modules with Atmel tech? You can check out our complete device breakdown here.