WirelessHART and ISA100.11a are two wireless protocols designed specifically for industrial applications. Based on the IEEE 802.15.4 wireless standards and utilizing Direct Sequence Spread Spectrum, these protocols provide robust and reliable low data rate wireless communications for a variety of industrial sensors and sometimes even controls.
While I dont have captures of these two protocols specifically, I do have several examples of what Frequency Hoping Spread Spectrum (FHSS) and DSSS looks like in spectrum analysis. The images below are examples of FHSS and DSSS from several different device deployments. While these are FHSS and DSSS, they are running on top of proprietary protocols as opposed to IEEE 802.15.4.
The image above is from a deployment of Lorex LW2232 wireless cameras utilizing FHSS across the 2.4GHz spectrum. The deployment consisted of twelve cameras and transceivers all transmitting at their full power capacity of 16dBm. As you can see, at these levels they were disrupting the coexisting Wi-Fi due to the high utilization.
This is a capture I took in my lab while testing several Phoenix Contact RAD900 Wireless IO devices. These run on a proprietary protocol on 900MHz, but still used DSSS for frequency transmission. You can see the communication is very organized and while there is a lot of data going back and forth, the actual bursts of communication are very small. This helps dramatically with contention for airtime.
This capture was from a network of Banner Engineering 900MHz sensors around a waste water treatment facility. Though there were over twenty devices in the network, you can see that there is plenty of airtime and no contention. Though Banner uses proprietary protocols, DSSS keeps the data flowing reliably and continuously.
If you would like to learn more about WirelessHART, check out these links:
FieldComm Group: https://www.fieldcommgroup.org/technologies/wirelesshart
If you would like to learn more about ISA100 wireless, check out these links:
Yokogawa – https://web-material3.yokogawa.com/fld-field-test-report-vol01.pdf
Rfwireless-world – https://www.rfwireless-world.com/Tutorials/ISA100-wireless-tutorial.html
ISA100 and the OSI Model – https://isa100wci.org/about-isa100-wireless/isa100-and-the-osi-model
If you would like to connect with me or learn more about my employer, Global Process Automation (GPA), then check the following:
Scott McNeil – https://www.linkedin.com/in/americanmcneil/
The Industrial Wi-Fi Shop 