Looking for ideas to log equipment down time

[Chris W]

Here is the problem. A client company has about 100 pieces of equipment
that they want to track when and how long they are down for service.
The equipment can be a few hundred feet from the nearest computer. The
requirement is for one computer to track every piece of equipment. The
interface will simply be the user equipment operator hitting a button
when the equipment goes down and then hitting another button when it
goes back in service or a toggle switch. Most likely a red and green
button with a corresponding red and green indicator LED. The software I
will write will log changes in the status of the equipment into a
database.

My first thought is to use a USB digital IO board and use network
cabling to connect the switches to the IO board.

Any other ideas?



--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Ham Radio Repeater Database.
http://hrrdb.com

 

[Baron]

Here is the problem. A client company has about 100 pieces of
equipment that they want to track when and how long they are down for
service.
The equipment can be a few hundred feet from the nearest computer.
The
requirement is for one computer to track every piece of equipment.
The interface will simply be the user equipment operator hitting a
button when the equipment goes down and then hitting another button
when it
goes back in service or a toggle switch. Most likely a red and green
button with a corresponding red and green indicator LED. The software
I will write will log changes in the status of the equipment into a
database.

My first thought is to use a USB digital IO board and use network
cabling to connect the switches to the IO board.

Any other ideas?

If they are networked you could track the mac addresses.

 

[Chris W]

If they are networked you could track the mac addresses.

Just to clarify, the pieces of equipment in question are NOT computers
and there are NO computers near the equipment. A signal must be sent a
few hundred feet to another room on another floor in the building to the
nearest computer to do the logging. Also the equipment is not all in
the same place.

--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Ham Radio Repeater Database.
http://hrrdb.com

 

[Mike Silva]

I bet somebody has a really clever solution for this, but until then
I'll offer a thought. An important goal would seem to be to keep the
wiring effort to a minimum. If you're going to have LEDs you're going
to have some power at the switches. What about an 8-bit parallel-to-
serial shift register at each switch. Encode the bottom 7 bits with a
switch ID using some form of jumpering, and use the top bit to hold
the switch state. Wire all the boxes in series and then to read the
switches you supply a single LOAD pulse followed by 800 clock pulses
to read in 100 switch-ID-and-status bytes.

If you guarantee that the tail end of the wiring string always feeds
1s to the last SR (wire up each SR input with a weak pullup), you can
just send out bursts of 8 clock pulses until you read back a value
with all 1s, indicating that all the connected boxes have been
polled. In this case you just don't use the switch ID value of 0x7F
as a valid ID. Then also, if you have a break in the data line, you
will get an all-1s byte before you have read all your switches and you
will be able to detect that. You'll also need to analyse what your
return signal will look like with breaks in the V+ line, GND line,
LOAD line and CLK line, but in any case it will be easy to distinguish
any of those from valid data.

Mike

 

[Mike H]

Here is the problem. A client company has about 100 pieces of equipment
that they want to track when and how long they are down for service.
The equipment can be a few hundred feet from the nearest computer. The
requirement is for one computer to track every piece of equipment. The
interface will simply be the user equipment operator hitting a button
when the equipment goes down and then hitting another button when it
goes back in service or a toggle switch. Most likely a red and green
button with a corresponding red and green indicator LED. The software I
will write will log changes in the status of the equipment into a
database.

My first thought is to use a USB digital IO board and use network
cabling to connect the switches to the IO board.

..

First thing that comes to mind is something using the 1-wire network
devices from Maxim (formerly Dallas Semiconductor).
http://www.maxim-ic.com/auto_info.cfm

The devices have an internal hard coded unique serial number and often
some ram so you can store attributes of equipment. You can communicate
with them over a pair of wires on a shared network. Using the I-
buttons you could have a tech or operator touch a touch-point to take
it out of service, then another to take it back into service. I bet
you could get creative with it.

 

[Rich Grise]

Here is the problem. A client company has about 100 pieces of equipment
that they want to track when and how long they are down for service.
The equipment can be a few hundred feet from the nearest computer. The
requirement is for one computer to track every piece of equipment. The
interface will simply be the user equipment operator hitting a button
when the equipment goes down and then hitting another button when it
goes back in service or a toggle switch. Most likely a red and green
button with a corresponding red and green indicator LED. The software I
will write will log changes in the status of the equipment into a
database.

My first thought is to use a USB digital IO board and use network
cabling to connect the switches to the IO board.

Any other ideas?

You're going to need at least two wires to each box, preferably 3: common,
"down", and "up". In an industrial setting I might even recommend four
wires (two twisted pairs, much like telephone wire); then for a protocol
use 4-20 mA current loops. You'd need as many receivers as there are
equipments, or maybe two, since you need two signals from each equipment.

These receivers "should"* be a 4-20 mA interface for each channel -
I can't imagine these not being available commercially. The advantages of
the 4-20 mA loop are incredible noise immunity, and there's a built-in
fault (e.g., broken wire) detector: if there's (are?) 0 mA in the loop,
it's broken. (that is, 4 mA means "start" and 20 mA means "end" or however
you want to arrange it.)

You might want to try a google search on "4-20 mA receivers" or
thereabouts.

Good Luck!
Rich
* should: the way I would do it. ;-)

 

[Joerg]

Here is the problem. A client company has about 100 pieces of equipment
that they want to track when and how long they are down for service. The
equipment can be a few hundred feet from the nearest computer. The
requirement is for one computer to track every piece of equipment. The
interface will simply be the user equipment operator hitting a button
when the equipment goes down and then hitting another button when it
goes back in service or a toggle switch. Most likely a red and green
button with a corresponding red and green indicator LED. The software I
will write will log changes in the status of the equipment into a database.

My first thought is to use a USB digital IO board and use network
cabling to connect the switches to the IO board.

Any other ideas?

If there is Ethernet in all those rooms you can use LAN-LabJacks. But
they are about $400 a pop.

Simpler solution: Post a phone number, an "equipment down" code and an
"equipment operational" code number on each machine. Use a telephone
interface at the PC and let that be the only thing answering this
number. The rest is, ahem, ducking for cover here, just software.

 

[whit3rd]

Here is the problem.  A client company has about 100 pieces of equipment
that they want to track when and how long they are down for service.
The equipment can be a few hundred feet from the nearest computer.  The
requirement is for one computer to track every piece of equipment.  

How about getting a few cheap Palm PDAs, and let the maintenance
folk take one to the machine, open the datebook and add a notation
'#7734 OFFLINE' with the current date/time. At day's end,
return the PDA to its dock, and let 'em all sync (Bluetooth or
otherwise)
to the master datebook.

Overkill, but mass produced PDAs are cheaper than running
wires and installing buttons.

 

[Chris W]

Thanks for all the suggestions. I think I like the phone system idea
the best.


--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Ham Radio Repeater Database.
http://hrrdb.com