> Well, this is for mission-critical stuff, so we have a service contract 
> and all that kind of thing, so we basically get the hardware and software 
> they provide. But yeah, if support wasn't an issue, that's probably what 
> I'd do...

Yeh, guess you don't want to be held responsible when it breaks for 
something mission critical, better to be able to pass the responsibility on 
(even if they haven't updated their software since Win3.1!).

Still, you could encourage them to make some updates (like using USB instead 
of serial, and writing software for XP/Vista rather than Win3.1), or buy the 
system from a more up to date supplier that is less hacky.

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scott wrote:

> Yeh, guess you don't want to be held responsible when it breaks for 
> something mission critical, better to be able to pass the responsibility 
> on (even if they haven't updated their software since Win3.1!).
> 
> Still, you could encourage them to make some updates (like using USB 
> instead of serial, and writing software for XP/Vista rather than 
> Win3.1), or buy the system from a more up to date supplier that is less 
> hacky.

Well now, if you want a couple of thermometers and a data logger, 


it's mission critical. What are you gonna do? You simply *have* to have 
this thing, so basically you have to pay whatever they charge you. Which 
is probably _why_ they charge you so much. ;-)

I wasn't in any way involved in the purchase process, but I gather that 
we were quoted tens of thousands of pounds by various parties, and we 
eventually went with the lowest bidder. As far as I know...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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> Now if you write the words "mission critical" on it, suddenly the same 


Not really, I assume the hardware is of a much higher specification than 
some *really* cheap consumer version you could get for 20 quid.

> But hey, it's mission critical. What are you gonna do? You simply *have* 
> to have this thing, so basically you have to pay whatever they charge you. 
> Which is probably _why_ they charge you so much. ;-)

Usually you have the option of other suppliers, so the price should be 
pretty competitive for what you're getting. Otherwise they would go out of 
business if everyone else could sell the same product for half the price.

> I wasn't in any way involved in the purchase process, but I gather that we 
> were quoted tens of thousands of pounds by various parties, and we 
> eventually went with the lowest bidder.

If you were about to spend 10k on something, would you blindly take the 
cheapest one without even bothering to see exactly what you were getting? 
Sadly a lot of companies do exactly this, often with much larger sums of 
money...

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scott wrote:
>> Now if you write the words "mission critical" on it, suddenly the same 

> 
> Not really, I assume the hardware is of a much higher specification than 
> some *really* cheap consumer version you could get for 20 quid.


every 15 minutes. If they go outside a preset range, an alarm goes off. 
How much would *you* suggest such a system costs?

>> But hey, it's mission critical. What are you gonna do? You simply 
>> *have* to have this thing, so basically you have to pay whatever they 
>> charge you. Which is probably _why_ they charge you so much. ;-)
> 
> Usually you have the option of other suppliers, so the price should be 
> pretty competitive for what you're getting. Otherwise they would go out 
> of business if everyone else could sell the same product for half the 
> price.

Apparently all the suppliers we could find were charging 5 figures for 
something that will do what we want. Seems absurd to me, but... mission 
critical, gotta have one, gotta be up and running before date X...

> If you were about to spend 10k on something, would you blindly take the 
> cheapest one without even bothering to see exactly what you were 
> getting? Sadly a lot of companies do exactly this, often with much 
> larger sums of money...

Well, you'd hope so... but as I say, I wasn't really involved in the 
process. I believe the hardware was all much the same, so they went with 
the cheapest option from a supplier who could actually supply on time.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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> every 15 minutes. If they go outside a preset range, an alarm goes off. 
> How much would *you* suggest such a system costs?

Depends on far more than just the raw technical performance.

If I'm going to use it check the temperature in my greenhouse, I would 
imagine a 50 quid jobby from Maplins would do with some cheap hacked 
together Win3.1 program.  However, if I'm putting it in a manned spacecraft 
that is orbiting the moon, I would expect way higher performance, and an 
equally higher price.

BTW, the stuff we make here, we always have to put on the 1st page of the 
specification that it is not to be used in anything critical, like plane 
instruments, hospital equipment, traffic signals etc, simply because we 
don't design or test to high enough standards.  If we did, the cost would be 
astronomical, for stuff like PC monitors you don't need that level of 
reliability so you get them very cheap.

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On Thu, 15 May 2008 12:54:16 +0100, Invisible <voi### [at] devnull> wrote:

>
>Apparently all the suppliers we could find were charging 5 figures for 
>something that will do what we want. Seems absurd to me, but... mission 
>critical, gotta have one, gotta be up and running before date X...

Is the equipment and software certified? Because that adds to the
cost. 
-- 

Regards
     Stephen

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Invisible wrote:
> So, you have some equipment for monitoring temparature sensors and 
> logging their readings. And you supply some software that downloads this 
> data and lets you organise and examine it on a desktop PC.
> 
> You also supply your customers with a blob of software which, when 
> installed on a PC, somehow tricks the PC into thinking it has a new 
> serial port. All data sent to this port is *actually* tunnelled to the 
> little black box.
> 
> So, between the little black box at one end, and the custom software 
> driver at the other end, the hardware and software geniunely believe 
> they're still locally connected, yet actually they can be on different 
> continents.
> 
> Is this a valid solution to a design problem? Or is it a cheap hack?
> 
> [Did I mention that the "software" in question appears to be designed to 
> work with Windows 3.0? Does that change the answer?]
> 

If it is an existing system that needs to be made network 'aware' then 
it is a valid solution, but one that should be taken with caution.

Recently I built something that does exactly that.

I have some GPS modules that speak serial.
I built a custom serial/ethernet module.  But this one is smart - it has 
a buffer and built in web page for basic GPS info.
On the computer I run a ethernet/comm port emulator so that programs 
that expect only a comm port can work.
But one better, the serial/ethernet module allows for multiple 
connections - I can get multiple computers and applications pulling the 
same data on comm ports.

IMHO, a serial-ethernet module should be used as a last resort when 
there is no viable alternative.

If it is a mission critical application, then you are just introducing 
more points for failure.  When one of those points die, then it takes 
all that much longer to debug.


This reminds me of what would be put in at the GM-Saturn plant I worked 
in several years ago.  You kludge a bunch of stuff together until it 
works, then repeat and put 50 of them on the plant floor.  Even tho if 
one of them failed it would stop the production line.  I ran into some 
strange setups - parallel to serial to ethernet to serial to com 
port....  and in one case it took 3 days to figure out what piece failed.


Best of luck!

LAter... Tom

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scott wrote:

>> every 15 minutes. If they go outside a preset range, an alarm goes 
>> off. How much would *you* suggest such a system costs?
> 
> Depends on far more than just the raw technical performance.
> 
> If I'm going to use it check the temperature in my greenhouse, I would 
> imagine a 50 quid jobby from Maplins would do with some cheap hacked 
> together Win3.1 program.  However, if I'm putting it in a manned 
> spacecraft that is orbiting the moon, I would expect way higher 
> performance, and an equally higher price.

Well, we'd like to check that the blood samples we're storing actually 

about this fact, urgently.

I'm guessing a temparature sensor that actually *works* at temparatures 
that low is going to cost a tad more than your average room thermometer, 
but beyond that I don't see why it would need to cost more. It seems the 
only reason for the higher price is that this is a critical device, so 
the suppliers know they can charge the Earth and we will pay it. We have to.

> BTW, the stuff we make here, we always have to put on the 1st page of 
> the specification that it is not to be used in anything critical, like 
> plane instruments, hospital equipment, traffic signals etc, simply 
> because we don't design or test to high enough standards.  If we did, 
> the cost would be astronomical, for stuff like PC monitors you don't 
> need that level of reliability so you get them very cheap.

The mass spectrometers we have here all say "for research and 
development only; not for diagnostic procedures" on them. I can't 
imagine why - it's a mass spectrometer! Either it measures masses 
reliably, or it doesn't. If it does, you can use it for anything you 
like. If it doesn't, it's a worthless piece of equipment. So... why the 
sticker?!

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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Stephen wrote:

> Is the equipment and software certified? Because that adds to the
> cost. 

Not by the supplier, I don't *think*. Certainly *we* will be regularly 
checking it against an ISO standards-certified reference instrument 
[which really *is* insanely expensive]. But I don't *think* the 
suppliers actually provide any such guarantees - I'm not sure...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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> Well, we'd like to check that the blood samples we're storing actually 

> about this fact, urgently.


informed?  Would you trust a 20 quid meter from Maplin then?

> I'm guessing a temparature sensor that actually *works* at temparatures 
> that low is going to cost a tad more than your average room thermometer,

Not really, thermocouples are cheap (like a fiver) and measure down to 
below -100 degrees.

> but beyond that I don't see why it would need to cost more. It seems the 
> only reason for the higher price is that this is a critical device, so the 
> suppliers know they can charge the Earth and we will pay it. We have to.

Or the fact that there is a much lower chance it will break or mal-function. 
A simple example I can think of is that the connector where the thermal 
probe plugs in mal-functions somehow so that the electronics thinks that the 
temperature is -90 when really it is only -70.  Or some solder joint on the 
circuit board wasn't made completely correctly and messes up some other 
reading in an undetectable way once the temperature and humidity get to a 
certain value.  There are all sorts of failure mechanisms that needs to be 
checked and fixed somehow, and that costs lots of money.

> The mass spectrometers we have here all say "for research and development 
> only; not for diagnostic procedures" on them. I can't imagine why - it's a 
> mass spectrometer! Either it measures masses reliably, or it doesn't. If 
> it does, you can use it for anything you like. If it doesn't, it's a 
> worthless piece of equipment. So... why the sticker?!

Because they don't guarantee it will work reliably the whole time.  For them 
to guarantee that, they would need to do lots of expensive testing on every 
unit, probably design in lots of redundant systems, use more expensive 
components that have longer lifetimes, use better assembly methods etc.

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