Standards--whatever, was OPC or Mimosa for XML?

  • Thread starter Hullsiek, William
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Thread Starter

Hullsiek, William

Before going off and inventing your own standards, XML, or what-ever, you still need to come up with standard object model. This is probably where the real work is.

In fact, if you do your job correctly, you could use XML, DCOM, HTML, Mimosa, MMS or SNMP, CMIP, SOAP, ROAP, Modbus/IP or whatever, to communicate to the device.

In short, most people implement a protocol based the physical component they are communicating to. A PLC protocol looks like files or registers.

In MMS, efforts were spent on the virtual machine, and then a set of methods/properties were defined for the virtual machine. One then mapped the methods / properties to the protocol.

Once you design the object model, you then need to make it un-readable, and obtuse. Only then will it be considered by a standards body. One good alternative, is to make the standard for free, but then charge $100 for 'Standard XYZ For Dummies'. Charge money for the read-able version.

If we were following the lead of the IP authors, (Comer, et al), then put an implementation of the standard in a CD-ROM at the back of the book, with a set of programming conventions. But then that would make too much sense.

This industry likes to re-invent the wheel all the time and will be arguing about this for the next 10 years. Me thinks the Penguin PLC is going to make an impact.

William F. Hullsiek
MES Software Engineer