Wireless Solution Saves Time and Reduces Overheads for OT Machinery Monitoring Project

A new suite of monitoring devices would be attached to existing machinery — some having been in operation since the 1950s — and the data collected would need to be sent back to the main control room for analysis. For instance, a pump house was located away from the main building, which had been in operation 24 hours a day for over 40 years without any attention being given to its power usage over its output. Our customer planned to equip this machine with a Current Transformer — a standalone meter which clamps onto power input cables and monitors the flow of electricity during the machine’s operation. This data would then need to be fed back to a central location in a format which could be read and analysed by the facility management team.

This pump house also had existing meters monitoring water output and pressure, but these were not connected to the network, with their data having to be manually checked by maintenance staff periodically. Not only did this tie up valuable maintenance time but also issues would not be reported in real-time. Water pressure issues had occurred in the past and timely action not been taken due to the manual nature of the monitoring processes in place.

A lot of the machinery to be equipped with these monitoring devices were located far away from the main network, with some over 100 meters from any form of network connectivity. Due to the limits of traditional copper Ethernet networks, a single cable would not be able to support the distance required to transmit the data. Copper Ethernet cables can be extended but there was no existing infrastructure into which to install Ethernet extenders, and the work involved in cabling to these out buildings would have been cost-prohibitive for this stage of the project.

Power was also a potential issue, with most of the outbuildings using 3-phase AC. Firstly, a transformer would be required to step this down to 240v, and then an additional DC power supply would be required to power any of these new monitoring and connectivity devices.

Furthermore, maintenance windows were limited to two — one week around July and another over the Christmas period — so a wireless solution was desirable due to the limited impact of its installation to day-to-day operations. Traditional WiFi, however, also has distance limits, and antenna alignment over long distances has very little tolerance — something which could be a potential source of issues as the system is in operation.

To bypass the limitations of traditional WiFi and Ethernet, and to keep within the specification of low installation costs, Impulse put forward a solution using Advantech’s proprietary LPWAN devices. LPWAN is based on sub 1GHz radio frequency, which enables longer distance and higher signal penetration than regular WiFi, allowing for wireless data transfer between the main network and the devices located over 100 metres away in concrete out buildings. As LPWAN supports connectivity up to 5km (line of sight), this would allow for future expansion should more machinery need to be installed in other locations within the compound.

An Advantech WISE-4210 Access Point was put forward which was connected directly to the network and located on the outside of the main building in a waterproof enclosure. These WISE access points can support up to 64 nodes located up to 5km, which more than covered the requirements of the project.

A number of sensor nodes were used: for the machines where power was being monitored using Current Transformers, Advantech’s WISE-2210 sensor node was able to draw power from the Current Transformer itself, meaning no external or battery power was needed to operate these sensor nodes. Advantech’s WISE-4210 Industrial LPWAN sensor node was used for other sensors as it supported battery power, and with up to 5 years battery life, maintenance requirements for this aspect of the network would be minimal.

As the potential for analog input was discussed between the customer and our Network Engineers for phase two of the project, these Advantech WISE modules were a perfect fit due to their modular design. With a simple change of the input connector the device can be switched to support many different input combinations, including digital, analog, RS-485 and more.

To gel the solution together Impulse suggested that the customer used MQTT as the protocol to transmit the data, as most of the end devices have MQTT built in. MQTT enables many different types of devices to communicate over a publish/subscribe protocol, meaning multiple separate platforms can consume this data — something not possible with traditional SCADA solutions.

MQTT also allows for future expansion should the customer decide to move the data to the cloud to allow multiple sites to be analysed centrally.

Impulse Embedded can help with the transition to an IIoT solution, providing hardware from the server to the edge to facilitate simple monitoring applications through to full-scale AI deep learning systems. For more information about how Impulse can help with your next IIoT project, visit www.impulse-embedded.co.uk