K
Hello Again,
I just want to comment on the system architecture. Everyone is busy trying to promote languages, interfaces to the PLC (telnet, XML, etc.), and even trying to document APIs and function calls.
I am new to this discussion, so take this with a grain of salt, but I see absolutely no real published Ideas for how the system is to be
structured. Where are the block diagrams, where are the rough draft specs (or at least proposed specification ideas??)
I have a lot of experience designing hardware and software systems (That is a PLC isn't it??) ) and any good design starts with a good design
specification .... Having said that, even a good design spec is not perfect and needs to be modified as you go by careful communication of
ideas and concepts.
It is my understanding from reading the discussion threads that most people in the open source world seems to despise specifications and, to some extent, I can understand this. My fear is that this project is not going to be engineered, but that it is going to be pieced together with
the system architecture coming in as an after thought. If this is the case then this project will never really work the way it was intended.
BTW, Everybody who reads this needs to take a look at what Steeplechase software is doing.
http://www.steeplechase.com
They have an Excellent product that performs Hard Real time with a very elegant and powerful graphical front end that supports RLL and Flow
chart (Mainly flow ... RLL is for backwards compatability) It is fast as well. When the PLC portion is finished it still leaves enough time to
run Windoze NT as a Task. This is it's shortcoming, Windoze. It's structure and architecture should be considered as a model. (Look at the White Papers) I have worked with the folks who created the software (former AB employee) and they are top notch Software Engineers. I like the software, but like I said, it requires Windoze in order to load programs and to have a GUI. (Once it runs it is independant of Windoze, but a lot of windoze problems occurr when booting anyway!!)
Another concern of mine is that EVERYONE seems to try and divert the primary goals of this project. Simple. PLC. IO Driver interface. Basic HMI. All the fancy stuff can be added as long as the basic structure here is solid.
Thanks for bearing with my gripes. My intent is not to offend, but to promote this great project.
~Ken
_______________________________________________
LinuxPLC mailing list
[email protected]
http://linuxplc.org/mailman/listinfo/linuxplc
I just want to comment on the system architecture. Everyone is busy trying to promote languages, interfaces to the PLC (telnet, XML, etc.), and even trying to document APIs and function calls.
I am new to this discussion, so take this with a grain of salt, but I see absolutely no real published Ideas for how the system is to be
structured. Where are the block diagrams, where are the rough draft specs (or at least proposed specification ideas??)
I have a lot of experience designing hardware and software systems (That is a PLC isn't it??) ) and any good design starts with a good design
specification .... Having said that, even a good design spec is not perfect and needs to be modified as you go by careful communication of
ideas and concepts.
It is my understanding from reading the discussion threads that most people in the open source world seems to despise specifications and, to some extent, I can understand this. My fear is that this project is not going to be engineered, but that it is going to be pieced together with
the system architecture coming in as an after thought. If this is the case then this project will never really work the way it was intended.
BTW, Everybody who reads this needs to take a look at what Steeplechase software is doing.
http://www.steeplechase.com
They have an Excellent product that performs Hard Real time with a very elegant and powerful graphical front end that supports RLL and Flow
chart (Mainly flow ... RLL is for backwards compatability) It is fast as well. When the PLC portion is finished it still leaves enough time to
run Windoze NT as a Task. This is it's shortcoming, Windoze. It's structure and architecture should be considered as a model. (Look at the White Papers) I have worked with the folks who created the software (former AB employee) and they are top notch Software Engineers. I like the software, but like I said, it requires Windoze in order to load programs and to have a GUI. (Once it runs it is independant of Windoze, but a lot of windoze problems occurr when booting anyway!!)
Another concern of mine is that EVERYONE seems to try and divert the primary goals of this project. Simple. PLC. IO Driver interface. Basic HMI. All the fancy stuff can be added as long as the basic structure here is solid.
Thanks for bearing with my gripes. My intent is not to offend, but to promote this great project.
~Ken
_______________________________________________
LinuxPLC mailing list
[email protected]
http://linuxplc.org/mailman/listinfo/linuxplc