CAN-MD ® is a new digital sensing platform for machinery diagnostics. Smart sensing is here!
- Digital data transformation on the machine using highly configurable CAN-Bus based sensors with integral DSP micro-processors
- Digital bus-based single-cable installation reduces complex centralised hardware
- Highly expandable system with the capability to add channels
- Turns complicated broadband vibration data into CI’s that have actionable outcomes
CAN-MD ® Vibration Sensors
Firstly, vibration sensors (unlike temperature, pressure, inertia, load, and other slowly changing physical measurement parameters) produce incredible volumes of dynamic data. Secondly, streaming raw vibration data from multiple nodes in a bused environment is not possible. Due to the limitations of bus processing speeds. Prior to CAN-MD®, sensors capable of sophisticated machinery diagnostic functions were all-analogue. They had not transitioned to digital bus communication. CAN-MD ® has now solved the toughest machinery sensing challenge: going all-digital with high level, broadband vibration data processed at the source.
Digital solutions offer simpler wiring schemas by reducing down to one primary cable as opposed to the multitude of individual cable runs required by analogue systems. User-configurable firmware in the CAN-MD® platform optimises each individual monitoring location for the best possible results. The CAN-MD® platform coexists and operates within a variety of CAN protocols. Bridges can be sourced to convert to other bus protocols. Such as ethernet, RS232/RS485 and ARINC protocols to name a few.
CAN-MD System Description
CAN-MD® accelerometers post Condition Indicators (processed features from resident algorithms) on the bus automatically and/or, when instructed. They can also manually acquire data from one or more of the 63 acquisitions and 127 CI’s. Then generate and output that result to the bus.
Working Principle CAN is a broadcast-type bus. Firstly, a message transmitted by one line replaceable unit (LRU) is received by all the LRUs connected to the bus. Secondly, each LRU will have a filter to accept the message relevant to it. Data messages transmitted from any terminal on a CAN bus do not contain source address or destination address. Data messages are transmitted as a frame. In each frame, the message is labelled by an identifier. It is unique throughout the network that includes the Node ID and sensor serial number.
All other LRUs on the network receive the message. Each performs an acceptance test on the identifier to determine if the message and its content are relevant to that particular LRU. Since the information from each sensor includes the “Node ID” and sensor “serial number”, data verification is easily accomplished via a visual inspection of the sensor location to ensure the serial number matches the data.
Data and Condition Indicators in CAN-MD
A Condition Indicator (CI) is the result of the onboard DSP and algorithm processing functions performed by CAN-MD® sensors. Also, CIs are provided as outputs on the CAN bus. They are the primary bits of information sent to dashboards, either locally or in the Cloud. This is the most significant part of the CAN-MD ® system. CIs can be used to trend developing faults. It can also predict failures, or to signal “normal, warning, shut down, alarm, green, yellow, red” or other operating conditions as selected.
CAN-MD® sensors can boot up and start collecting and processing CIs automatically. These CIs are filtered with information to classify “operating mode” dependent results. CAN-MD® sensors can respond to commands over the data bus. These commands can be an order to collect synchronous or asynchronous measurements and output processed or raw data on the CAN bus. Sensor data is requested from a particular sensor. Also it is stored in a data logger via a simple user interface. Raw data is not stored on a repetitive basis. Because of its large file size and long transfer times. It is tremendously useful in debugging or analysing difficult vibration problems and setting up associated CIs in the future.
CAN-MD ® distributes data processing across the entire network rather than through one central processor. This built-in redundancy reduces the “single point failure” associated with traditional monitoring systems. This means each sensor has its own address. The setup configuration is stored at sensor level. Rather than on a central processor. Therefore by default, the firmware on each sensor is physically partitioned so that changes are made locally down at the sensor, thus simplifying validation and verification (V&V) of any firmware updates.
Traditional Vibration Health Monitoring Systems
Finally, in traditional VHM (Vibration Health Monitoring) systems, simple changes can force complete “end to end” testing. This is to prove those changes don’t affect other operations on the main LRU. You can augment existing VHM systems with CAN-MD. As the host processor would only have to allocate the additional bus traffic from CAN-MD®. This is especially useful when an existing VHM system has reached analogue vibration sensor capacity (channel count is maxed out); CAN-MD® can augment the system with additional channels without having to force an LRU change or a system redesign.
Dytran / Sage Partnership
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