Tuesday, 4 August 2020

Politically correct automation terminology!

Political correctness has reached technical terminology a recent communication from CiA's Holger Zeltwanger reminds us. For many years, terms multi/master, black/white listing, and male/female connectors have been used. Plug substitutes male and socket is used instead of female. So far, so good. Can in Automation (CiA) has already cleaned up its specifications regarding connectors.

Controller Area Network (CAN) has been categorized as multi-master approach since its introduction in 1986. To be more precise, it is a publisher/consumer system. Each node is allowed to transmit at any time data or remote frames. Depending on the frame priority, it gets bus access sooner or later. This means, we do not need the term master for the CAN data link layer description. This is true for all three CAN protocol generations: Classical CAN, CAN FD, and CAN XL.

CAN-based higher-layer protocols such as CANopen introduce a master/slave behavior for NMT (network management) services, for example. In electronics and software technology, the term master/slave is used frequently. It describes a model of asymmetric communication or control, in which one device or process (the master) controls one or more other devices or processes (the slaves) and serves as their communication hub. In some systems a master is selected from a group of eligible devices, with the other devices acting in the role of slaves. Since 1976, the master/slave term has been used in more than 67 000 U.S. patents. Now, we are looking for a politically correct term. There are many proposals hanging around: primary/secondary, leader/follower, parent/child, etc. (In passing, he comments that the term leader should not be translated into German!)  Perhaps captain/steward might be added to the proposals indicating the command hierarchy on ships and in aircrafts.

"CiA has not used frequently black/white listing. The proposed term deny/allow lists seems to me acceptable."

Of course, there are more political correct options. "Only one should be used in the CAN, says Zeltwanger, "and proposals and suggestions are welcome."

@CANopen #PAuto 

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