R
Ralph Mackiewicz
> > So you too wonder about why things are done the way they are in the
> > world of controls. So do I.
>
> Of course no major manufacturer actualy WANTS an open protocol that
> will allow small vendors to tap into their user base, or lay
> themselves open to competion. It is the customers responsibility to
> INSIST on openess for thier own protection.
Yes EXACTLY. There is a lot of hand-wringing about all the proprietary stuff used in IA but it is mostly misdirected. Customers buy all that proprietary stuff. That is why it exists.
> In IA communications products tend to have a very high degree of
> conformance to one of the plethoria of 'standards' out there.
In the words of Bob Metcalfe, co-inventor of Ethernet: "Standards are great. Everyone should have one of their own." He was being sarcastic.
> Unfortunately that does not assure interoperability as standards fall
> short of defing every element required in a connection, there is
> always space to make a conformant device not interoperate with another
> conformant device, often in a conformant manner!
Such interoperability issues are inevitable in ANY standard. We are all human beings and it is not possible to define a *useful* comm standard (if the standard is too rigid it becomes too narrow in its scope...flexibility brings choices) that does not provide some choices to the developer. Not being conspiratorial in nature, and
based on long experience implementing public communications standards, anytime there are choices each developer will likely make different choices. Not to purposely foil interoperability, but due to simple human frailty.
> Also, while manufacturers are quick to stick standards labels on their
> products, technical support frequently refuse to help resolve problems
> in a system where an alternative (compliant) product has been used for
> some element in place of their own product. i.e. Connect foo
> engineerings PLC to foo engineerings DP encoder with baa engineerings
> capable, when things do not work (even if there is no sign of comms
> problems) the first thing they suggest is to replace baa engineerings
> cable with thier own.
This is a shame but it is not universal. You shouldn't put all 'manufacturers' in the same bag. My company has worked with numerous customers in working through interoperability issues that resulted in identifying bugs in our competitors product as well as our own. We have even made changes in our product to interoperate in spite of other people's bugs. If you are committed to standards dealing with
interoperability is a simple fact of life. Those manufacturers that you have this problem with are not committed to standards. Probably because most of their customer base is perfectly satisfied with a proprietary approach.
> That is why many people regard the only real open systems to be open
> source ones. It is the only way that eventual problems can be
> identified and rectified.
Its not the only way, it is one way. You can also have a committed vendor. You can also buy product source code in some cases (albeit not "open source").
Regards,
Ralph Mackiewicz
SISCO, Inc.
> > world of controls. So do I.
>
> Of course no major manufacturer actualy WANTS an open protocol that
> will allow small vendors to tap into their user base, or lay
> themselves open to competion. It is the customers responsibility to
> INSIST on openess for thier own protection.
Yes EXACTLY. There is a lot of hand-wringing about all the proprietary stuff used in IA but it is mostly misdirected. Customers buy all that proprietary stuff. That is why it exists.
> In IA communications products tend to have a very high degree of
> conformance to one of the plethoria of 'standards' out there.
In the words of Bob Metcalfe, co-inventor of Ethernet: "Standards are great. Everyone should have one of their own." He was being sarcastic.
> Unfortunately that does not assure interoperability as standards fall
> short of defing every element required in a connection, there is
> always space to make a conformant device not interoperate with another
> conformant device, often in a conformant manner!
Such interoperability issues are inevitable in ANY standard. We are all human beings and it is not possible to define a *useful* comm standard (if the standard is too rigid it becomes too narrow in its scope...flexibility brings choices) that does not provide some choices to the developer. Not being conspiratorial in nature, and
based on long experience implementing public communications standards, anytime there are choices each developer will likely make different choices. Not to purposely foil interoperability, but due to simple human frailty.
> Also, while manufacturers are quick to stick standards labels on their
> products, technical support frequently refuse to help resolve problems
> in a system where an alternative (compliant) product has been used for
> some element in place of their own product. i.e. Connect foo
> engineerings PLC to foo engineerings DP encoder with baa engineerings
> capable, when things do not work (even if there is no sign of comms
> problems) the first thing they suggest is to replace baa engineerings
> cable with thier own.
This is a shame but it is not universal. You shouldn't put all 'manufacturers' in the same bag. My company has worked with numerous customers in working through interoperability issues that resulted in identifying bugs in our competitors product as well as our own. We have even made changes in our product to interoperate in spite of other people's bugs. If you are committed to standards dealing with
interoperability is a simple fact of life. Those manufacturers that you have this problem with are not committed to standards. Probably because most of their customer base is perfectly satisfied with a proprietary approach.
> That is why many people regard the only real open systems to be open
> source ones. It is the only way that eventual problems can be
> identified and rectified.
Its not the only way, it is one way. You can also have a committed vendor. You can also buy product source code in some cases (albeit not "open source").
Regards,
Ralph Mackiewicz
SISCO, Inc.