Addressing the challenges of industrial automation systems

1. Low power + performance

There are prominent and recurring challenges across all market sectors that are just as prevalent in factory automation. At the forefront are the needs for a system to reduce power consumption. In our basic system, temperature sensors may be wireless and require batteries that last as long as possible (in some cases, over 20 years). In addition, when a factory uses a 4–20mA current loop for communication, there is a typical max current budget of less than 3.5mA on the loop. With such limited current, the MCU needs to consume as little energy as possible. MSP microcontrollers continue to lead the industry in power-optimized applications. The key to achieving the lowest power consumption is recognizing that power is more than one number. Some systems require the lowest standby current consumption, others require higher performance with low active current consumption, and many require a combination.

Beyond the basics, there is a need to reduce energy consumption required to read and store sensor data as well as to optimize application software.

TI’s ultra-low-power MSP MCUs with Ferroelectric Random Access Memory (FRAM) are perfect for applications that spend the majority of time in standby or need to log data. They consume as little as 350 nA of current with the real-time clock enabled and are able to write 13 KB of data to nonvolatile storage in milliseconds, not seconds.

They even provide more computational performance with optimized math libraries that can be leveraged in combination with the 100 µA/MHz active mode current for efficient operation. If 32-bit performance is needed, the MSP432™ MCU series offers up to 48-MHz operating frequency and an ARM® Cortex®-M4F core that still delivers best-in-class active-mode current consumption of 90 µA/MHz.

Moreover, unique optimization utilities including EnergyTrace™ technology are available to deliver unmatched real-time power profiling for MSP MCUs.
 
2. Making smarter designs

Once power concerns are addressed, system integration becomes a key priority. High performance analog does not need to be integrated in the microcontroller (MCUs usually have serial communication ports including SPI, I2C or UART for communication to external interfaces), but doing so can simplify development and help to reduce overall system power consumption and size. The MSP MCU portfolio contains chipsets with a high degree of on-chip analog integration, perfect for quick and easy implementation of factory automation applications. Many MSP MCUs contain 10-, 12-, and 14-bit ADCs and DACs, operational amplifiers and comparators. In particular, the MSP430i2x MCU family features four on-chip 24-bit Sigma-Delta ADCs. Specialized peripherals are also available. The extended scan interface, available in the FRAM MCU series, is an analog front end that enables flow measurements that consume less than 9 nA per sample in a two-sensor system using induction, magnetic or optical sensors.

Using FRAM-based microcontrollers in a system can improve system efficiency in other ways as well.

FRAM offers a unified location to store application and data with the flexibility to adjust the allocated proportions as development needs change.

What’s more, on-the-fly, bit-level data writes that do not require buffering or pre-erase means that wireless transmissions can be shorter. This is critical to battery-powered systems, where wireless communication often consumes the most energy in the system (Figure 3). This also means that over-the-air updates will consume less power and be simpler to handle in software. Finally, if power does fail, the Compute Through Power Loss FRAM utility enables your system to restore system state after power failure with two lines of code and no backup power source required.


 
Figure 3: Field transmitter featuring HART® communications.


These features all come together on MSP MCUs to create system-on-chip solutions that can handle analog sensor inputs, output directly on 4–20mA current loops and run communication protocols.
 
3. High operating temperature

High temperatures are common in many aspects of a factory’s production line. Sensor nodes are often placed close to processes that generate a lot of heat and need to withstand high temperatures.
One example is a sensor node used for equipment monitoring. Rather than use a handheld meter to ensure motors in a factory are operating correctly, remote sensor nodes can run calculations on vibration data and transmit that data to a central hub. In cases, where that equipment runs hot, the MSP MCU portfolio offers wide operating temperature ranges across Flash and FRAM products. The MSP430F2xx MCU family in particular, contains MCUs that operate at temperatures up to 105 °C, 125 °C and even 150 °C.