Re: Analog to Digital converters/controllers?

OK. Based on the specs of that device, I'd use Ethernet, not USB, for
communications with the I/O, generally. As mentioned, you can probably find
some RS232-based controllers, if you prefer, but then you'll have to come up
with USB-to-serial adapters in order to get RS232 ports, etc. I don't think
it's worth that (if you had actual serial ports built-in, that would be a
good choice). If you just use Ethernet-based I/O, all you need is a hub and
a couple of cables (and, of course, the API for controlling your I/O).
RS232-based I/O is likely to be cheaper per-channel, so, if it's a hobby
project, you might want to do that anyway, but for a real application, I
wouldn't. As mentioned, if you use USB-based I/O, you're going to need CE
drivers for those devices and I don't know of anyone who makes such things
for their USB devices.

What's the critical parameter of all this? Price? You're probably best
with RS232 and devices that have individual channels that match exactly what
you need, in that case, although you'll have to see what you can do about
your linear actuator, if anything (you didn't say how you were going to use
that, so it's hard to say, yes, you need X or Y or Z). If you want
expandability or single-device implementation of all of the functions, a PLC
or something like our EDAS CE can do it, at higher cost, with a lot of extra
capability (you can't buy 1 channel of analog input from us, so, if you need
1, you get 16; whether that's good or not depends on your application).

The biggest player in test/measurement is National Instruments. They're
fairly predatory and I hate to point you to them, but they are there.
Dataq, as mentioned, is a good company. IOTech is another. One that I
hadn't heard of until doing a Google search on "rs232 data acquisition
analog" was SuperLogics. They have things that would work for you. Take
care when buying "relay output" devices, however, unless you're just going
to use them to drive your own AC relays. Relays typically used in "relay
output" devices wear out quickly when controlling AC, rather than DC.

Paul T.

"JohnKoz" <JohnKoz@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:1312A077-88A0-4BA0-A2C5-970CA00A4852@xxxxxxxxxxxxxxxx
Thanks Paul,

I see where you're coming from, let me try to restate what I'm looking
for.
I'd like to locate devices that allow me to interact with the 'environment'
from my WinCE device (assume VIA ARTiGO).
Such a device would plug in via USB, RS232 or any other convenient
interface. It would enable me to programmatically:
. Measure a thermocouple or other temperature-sensing device.
. Energize a relay - The relays I would drive are 24VAC, but I don't have
to
drive them directly, i can drive a 5vdc relay so don't worry too much
about
the voltage amount or type.
. Detect if a relay is energized

I'm looking for shipping products that can do this. I'm not sure how/where
I
should look for them. Are they DAC's, or digitizers, or something else.

Do you have any links to vendors, dealers or devices?

Thanks

-John

"Paul G. Tobey [eMVP]" wrote:

I'd like to be able to measure and control external devices. For
example:
. Measure temperature of a room

No problem. You generally will do this with a thermocouple, although
there
are other temperature-sensing devices that are more-linear for
applications
which don't have to deal with very high or very low temperatures. Is
there
already a sensor in the room that you want to read or do you want to
implement one?

. Detect if a 24vAC relay is energized

This is a relay that you aren't controlling? I mean, if you control the
relay, you'd know, right? Otherwise, you'd need a 24 VAC input, which is
kind of strange range. We have devices that can do it, but for one
relay,
it's expensive.

. Control 24vAC relays

What is the control voltage? Most PC-based (plug-in board), control
boards
will have 0-5VDC outputs, which might not drive enough current to control
your relays. You need to know the specs for those relays when you're
looking for hardware to control them. Generally, though, no problem.

. Control a linear actuator

This is a little big vague. You have the actuator? What control signals
does it use?

There are many companies who do this sort of thing. We aren't huge in
linear actuators, although we do have quadrature inputs for reading
position
from such things, step #1 in controlling them. We can do the other
things
with several different types of devices from plug-in boards for PCs, to
Ethernet-connected systems running RTOS, to programmable Windows
CE-based,
Ethernet-connected devices which are modular. Take a look at
www.edasce.com
and www.instrument.com, if you're interested.

If you want a magazine for this sort of device to see who's big in the
market, look and Test and Measurement World. I think you can find it at
your magazine shop. There will be ads in there from many folks who do
that
sort of thing with various interfaces.

Generally, if you're planning to build your own Windows CE-based device,
you
DO NOT want to interface to your measurement/control equipment with USB.
You need USB drivers for any equipment that you want to talk with and
almost
no one has Windows CE drivers for their USB devices.

RS-232 is no problem, of course, as you're basically writing your own
code
to control things anyway. Our devices have APIs for doing operations
like
reading all the analog input channels on a given device or writing all of
the digital output channels, or pulsing a digital channel for a period of
time. The other guys who do this have similar methods that vary
depending
on the various hardware architectures. Some offer high-level programming
environments for writing your 'program' graphically, as well as C/C++,
etc.
Others may have application environments that automatically acquire data
and
store it on disk or something.

Paul T.

"JohnKoz" <JohnKoz@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:45FB0C1A-C8C5-4341-BAC1-ED4348444925@xxxxxxxxxxxxxxxx
Hi,

I'd like to be able to measure and control external devices. For
example:
. Measure temperature of a room
. Detect if a 24vAC relay is energized
. Control 24vAC relays
. Control a linear actuator

I'm assuming such devices communicate with standard USB or RS232
interfaces,
I'm open to either, perhaps even Ethernet. Ultimately I'd connect this
to
a
CE embedded device, but I could also use it on my development
workstation
for
initial experimentation.

I don't know anything about the companies or individual products in
this
area. Do you have some suggestions that could get me started?

Thanks

-John






.

Relevant Pages

  • Re: Analog to Digital converters/controllers?
    ... I'm not worried about the actuator, it's going to degenerate to a relay ... Such a device would plug in via USB, ... What is the control voltage? ...
    (microsoft.public.windowsce.embedded)
  • Re: Analog to Digital converters/controllers?
    ... i can drive a 5vdc relay so don't worry too much about ... are other temperature-sensing devices that are more-linear for applications ... What is the control voltage? ... DO NOT want to interface to your measurement/control equipment with USB. ...
    (microsoft.public.windowsce.embedded)
  • Re: Analog to Digital converters/controllers?
    ... your linear actuator, if anything (you didn't say how you were going to use ... care when buying "relay output" devices, however, unless you're just going ... Such a device would plug in via USB, ... What is the control voltage? ...
    (microsoft.public.windowsce.embedded)
  • Re: Analog to Digital converters/controllers?
    ... Measure temperature of a room ... This is a relay that you aren't controlling? ... What is the control voltage? ... DO NOT want to interface to your measurement/control equipment with USB. ...
    (microsoft.public.windowsce.embedded)
  • Re: Basic Windows Security Question
    ... that can control removable media (usb thumb drives/mp3, firewire, ... To control access, GFI LANguard P.S.C. installs a small footprint ... > USB thumb drive. ...
    (Security-Basics)