Modern Machine Shop

JAN 2018

Modern Machine Shop is focused on all aspects of metalworking technology - Providing the new product technologies; process solutions; supplier listings; business management; networking; and event information that companies need to be competitive.

Issue link:

Contents of this Issue


Page 25 of 163

DECIDING FACTORS MMS JANUARY 2018 24 Data-Driven Manufacturing software to show which machines on a network are running or not running. In comparison, OPC UA does not have a stan- dard dictionary. When using OPC UA, it is neces- sary to know the address (or addresses) within the PLC where the running state (the equivalent to "execution") is stored. This data location is likely to vary across different types of equipment. The end user will need to do some research to find where it is, and may need to process the data to derive the desired result. This makes it more difficult for software to report whether the machines or devices are running. Yet OPC UA has its advantages. Although MTConnect is extensible (that is, more terms can be defined and added to its dictionary), the user is usually limited to the data items given in the MTConnect standard. The range of data available through OPC UA is greater because it is not con- strained by a dictionary of available terms. A driver is needed for OPC UA to retrieve data from the PLC. This driver is a software utility written specifically for this purpose to be used on a specific device. OPC UA drivers are readily avail- able for many PLCs from a variety of vendors. In contrast, MTConnect requires someone to develop the MTConnect adapter, which is the software that collects the data from the machine and formats it for the MTConnect agent. The MTConnect agent, in turn, enables the data to be accessed by analysis and reporting software. MTConnect adapters may not be available for many types of machine tools or CNCs. (It should be noted here that, in some cases, OPC UA has been used to acquire data, which can then be provided to an MTConnect adapter for standard formatting.) If MTConnect is available in the equipment to be monitored, it is generally the best option for this shopf loor application by virtue of its standard terminology. Significantly, the organizations that oversee MTConnect and OPC UA have worked together to make these standards compatible. This step ensures that, as the industrial internet takes shape, no machine or automated system will be left behind. CONTRIBUTOR | Josh Davids President and CEO, Scytec Consulting Inc.,

Articles in this issue

Links on this page

Archives of this issue

view archives of Modern Machine Shop - JAN 2018