WinNT Real time performance

R

R A Peterson

<<
>If a user needs access to an executable, why not simply assign access in the policy to his id or group?

A user can develop/install software that is available to him, or just his group, without requiring the intervention of somebody with
Administrator level priviledges. The advantage of this is only really appreciated on large systems however, not your typical NT setup, I
certinaly think it is a non issue for control apps. >>

This is not generally so. most software requires registry changes which a typical user cannot do. i got so tired of having installs die on me that I
changed my normal login to be an admin as well. its too much hassle to have to keep logging off to install a piece of software.
 
R

Ranjan Acharya

Just to add my two-pence worth since this has turned into the semi-annual Linux versus Windows NT debate.

1. Which flavour of Linux are you talking about? Not as badly fragmented as Unix yet, but getting there.

2. Do you have time to go into the source code of Linux and fix bugs. I do not. Many service calls are at obscene hours in out of the way locations, I cannot imagine wanting to spend extra time there investigating problems with the OS source code or a driver source code.

3. If you did fix a bug (for free, whose customer is going to pay for the time you spend playing with Linux?), who is going to pay for the additional time to go out and report it and so on.

4. Does Linux have the depth of support in the marketplace that NT has?

5. In "normal" installations of Windows NT, how many problems are people really having. We have installed several SCADA packages under the NT
umbrella -- Wonderware, RSView, FactoryLink, Intellution and so on. They all work fine. We have also installed AB's NT-engined PLC, it works fine too. From personal experience, if you use a good-quality well-engineered PLC with off-the-shelf standard parts, then you should be fine. The downside of NT is when you stray from the norm -- big trouble.

6. Straight Windows NT is not real time. Nor is straight Linux.

I still personally prefer a sealed automation solution where the operating system is irrelevant.

Ranjan Acharya 905-634-0844 x 238 (V)
Team Leader - Systems Group 905-634-9548 (F)
Grantek Control Systems http://www.grantek.com/
[email protected]
[email protected]
 
V

Vitor Finkel

I have no idea, but I wonder: What happens when the "egg" battery dies. batteries don't die suddenly, their voltage grows smaller and smaller till the device stops working or starts to work erratically.

Please ask your friend to do a "scientific experiment", replacing the "egg" battery with one quite used, and let us know what happens.


Vitor Finkel [email protected]
P.O. Box 16061 tel (+55) 21 285-5641
22222.970 Rio de Janeiro Brazil fax (+55) 21 205-3339
 
C

Curt Wuollet

roger Irwin wrote:

>...<clip>
> Oh I could go on, but lets stop there. I AM NOT TRYING TO START AN OS HOLY WAR, so please not get into the silly comments domain. I am hoping that people will tell me ways I can do these things on NT, or if not, why I am better off using it. I seem to be condemmed to use it at the moment 'just becuase everybody else does'.Somebody please give a better reason than that.<

Hi Roger,

You don't have to start an OS holy war. The automation market is like those last remote places in China where they never heard, didn't want to hear and didn't believe there was a war once they heard. The last stronghold where proprietary is a good thing, customer lock-in is to be admired and communication and interoperability are dangers to the state. The world that you and I know, where people use the same standards so we can cooperate and build on the work of others is a foreign fantasy, a big lie spread to corrupt and destroy this orderly
fuedal state. It is officially discredited by waves of propaganda telling the people they are already free and everything is already "open". What possible good could come from a common language or protocol?. No, the only good things are controlled by large companies that can prevent any that interoperability nonsense. The feudal lords all pay homage to the King and swear their allegiance in return for his favor. That's the way of things and you should be severely chastised for disloyalty and treason. Why that could start a mutiny or even rebellion.

Regards

Curt Wuollet, Owner
Wide Open Technologies.
 
Right. And the 60's were all about peace and love.

Competent people with good experience with just about any operating system can make them do what they need. This type of talk should go somewhere else. Can someone please create a new mailing list for this type of discussion - maybe it could be called: operating-system-religious-fundamentalism.
 
R
I think we are at cross purposes, I was pointing out why the individual permissions of POSIX like systems may be preffered over the poledit limitations of NT4.

'nix users always have thier home dierectory, which is the default place for their personal config data, not a common registry.

Actually I have often wondered why NT users cannot have their own 'home', complete with a personal registry.
 
R

R A Peterson

> 4. Does Linux have the depth of support in the marketplace that NT has? <

A better question might be to ask does NT have the depth of support you think it has? My experience with NT is that when it works it's great. When it has problems its a big time problem that often has no easily determined solution.

For example: my nice new laptop came with NT. I also have a nice new PC card modem/ethernet card. When I insert the PCCard and power up, NT locks up and I cannot even get the logon screen (I do get the message that says ctrl-alt-del to logon). All our NT experts and various tech supports at dell and 3com are baffled. So am I. I have reloaded various pieces of software and relaoded and removed so many drivers I am about sick.
 
D

Davis Gentry

> Can you compile an NT kernel and dynamicly configure
> it with modules? clip... How do you do it.

Yes - but you have to buy the Embedded NT toolkit from MS, plus the licenses. Not cheap, but reasonably painless to learn and use.

> Poledit from the Windows NT resource kit seems to be
> proposed ...

You have to buy the NT Resource Kit - it is a separate CD with utilities, etc. Been a while since I bought it - maybe $200??? Check with CDW.

> Thats a clever work around, is there any performance
> hit?

No more so than anything else done across the network - very dependent on traffic.

>Also, what
> about sec. issues. I assume that any user who will
> use such links must have network access to the
machine, i.e. an
> operators login can be used to access a machine
remotely.

Just set permissions under the security tab for the directory/drive when you set up the share. The user has to belong to a group which has permissions, or has to be specifically allowed to access the share.

Davis Gentry
Controls Engineer
Carpenter Company
 
D

Davis Gentry

>I would like to set up a system that will allow
someone make a ppp connection by dialing into the plant to initiate the connection, but then have the plant hang up the phone and dial back to
> complete the connection. I did it under Linux,
unfortunately, the program that I want to run on the remote system only runs under NT. I've search Microsofts knowledge base, done newsgroup searches, and web searches, but I haven't found any documents describing how to do it under NT.<

I'm out of town right now, but this seems kind of
interesting - I'm going to check it out when I get
back - maybe there is something on TechNet to describe it - when setting up a dial-up-networking connection you have the option to set it up as dial-up, or dial-up and call back. If it as set up as dial-up and call back you have to configure your RAS server to call back after authentication - but I just looked on my laptop running NTW 4.0 - RAS doesn't have anything
about call back - maybe it's just an NTS feature???

Davis Gentry
Controls Project Engineer
Carpenter Company
 
J

Johan Bengtsson

>> You can get that bare green screen on startup by using the policy editor found in the Windows NT Resource Kit (poledit.exe). <<
>
>Poledit from the Windows NT resource kit seems to be proposed as a
>solution to so many problems that I would expect to see it pole position
>on the Start Menu. Instead, I cannot find it at all. I carfully checked
>the 'custom'options on the install menu, and no mention of it. Is it in
>a service pack or something?

It is a program that comes with "Windows NT Resource Kit", something you have to get separately.


>> You can mount partitions (or directories for that matter) simply by sharing that partition or directory, then mounting the share name from your remote computer. ...<clip> <<
>
>Thats a clever work around, is there any performance hit? Also, what
>about sec. issues. I assume that any user who will use such links must
>have network access to the machine, i.e. an operators login can be used
>to access a machine remotely.

Everyone with a username and password that passes for an administrator on that particular computer can access these shares. The security for each file and directory is then added to this. (an administrator do probably have access to most files). What passes as an administrator on the comouter is anyone present in the local administrators group. This normally includes all domain administrators. Performance: same as for all other network shares.


>> If I fully understand symbolic links then there is a way to do this with NT. ...<clip> <<
>
>Not quite the same thougth is it. For example one use for symlinks is
>for dealing with programs that have thier own ideas about where
>files/directories should be. Another is for extending space on a full
>disk by moving chunks to another linked area. Sometimes you can get away
>with NT 'graX-Mozilla-Status: 0009s will not be fooled by this.

A symbolic link in *nix (as far as I have understood it) is what the windows .lnk file tries to provide (it don't succeed). It is a reference to something else but in *nix is is handled by the OS in a much more transparent way and can refere to a directory as well as to a file.


/Johan Bengtsson

----------------------------------------
P&L, the Academy of Automation
Box 252, S-281 23 H{ssleholm SWEDEN
Tel: +46 451 49 460, Fax: +46 451 89 833
E-mail: [email protected]
Internet: http://www.pol.se/
----------------------------------------
 
J

Johan Bengtsson

Actually they do have that.

The registry is composed of several files called hives. One of these files is personal and located in
%systemroot%\profiles\<user>
and called ntuser.dat
where %systemroot% is the instalaltion directory NT, typically c:\winnt

The things stored here is what you find in the registry under
HKEY_CURRENT_USER\...
personal data is preferably stored here:
HKEY_CURRENT_USER\Software\<company name>\<software name>\...

equivalent of user home directory:
%systemroot%\profiles\<user>\Personal\...
each users part of the desktop:
%systemroot%\profiles\<user>\Desktop\...


/Johan Bengtsson

----------------------------------------
P&L, the Academy of Automation
Box 252, S-281 23 H{ssleholm SWEDEN
Tel: +46 451 49 460, Fax: +46 451 89 833
E-mail: [email protected]
Internet: http://www.pol.se/
----------------------------------------
 
M

Michael Griffin

I saw one of these a few years ago. It was the size of a small card, and fairly thin. The LCD display on the front of it generated a new password on a regular basis. I was told that the way it works (and it seems fairly obvious) is that it has an accurate clock which is synchronised with a base unit which remains connected to the system you wish to log into. It may be possible that the base and portable units need to have their clocks re-synchronised occasionally though.

Both units generate a complex numerical series based on a common algorithm and seed (the seed is selected when the device is issued). At the start of each time interval, a new result is calculated. Since both devices execute a common algorithm, and since they were both initialised with the same seed, both will calculate the same result. The mathematical series is complex enough that it is not realistic to try to derive the original seed from a sample of calculated results. Passwords are unique to each device
pair, because of the different initialisation times and seeds.

These systems are supposedly very secure (at least the password is) - provided you don't lose the password generator. Unlike some systems, they
don't require any special hardware connection to the user's computer since the password is entered manually.

The cost and administration problems with this method seem to limit its use to applications where security concerns are higher than average.
They may have a use though where it is desirable to allow regular remote log-in to a plant control system (e.g. via the internet), but where security
problems could be serious.

**********************
Michael Griffin
London, Ont. Canada
[email protected]
**********************
 
C

C. Thomas Wiesen

I'm not expert, but I would agree. I think that there are a huge number of people with moderate "NT" experience but very few REAL experts that can identify particular driver problems and actually solve them (not band-aid patches or workarounds). I suspect that since Linux is open,
there are as many or more REAL experts that can identify and actually solve the weird hardware and software problems. Since NT is closed, only the author can help you fix a core code problem. With Linux, the code is usually available for you (or resident expert) to look at and debug.

--
C. Thomas Wiesen
Kukulu Automation
 
R
> Actually thay do have that

Yes they do don't they. You are right, but it is not obvious. Partly because they are 'seperate', but I think mostly because apps just do not tend to use things that way 'by default'.
 
A

Anthony Kerstens

One question about this "egg". Is it not something that could easily be stolen or lost? And if so, what's to prevent unauthorized users from making inappropriate use of it?

Anthony Kerstens P.Eng.
 
R

R A Peterson

until the guy looses the damn thing and now your secret password that changes all the time is known to the guy that found it.

changing your password is really not that great of a security measure except for accounts that are used by multiple people. my personal opinion is that all in all requiring chaining passwords on a regular basis for accounts that are only used by one person is counterproductive. its not all that easy to remember them sometimes and this leads to people writing them down, a major
problem. this is why i do not like passwords that are not easy to remember. people have to write them down or they forget, and this leads to security breaches.
 
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