"Almost" industrial I/O
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I need some interface to control 3 motors and read in some switches.
Because PCI-cards or remote-I/O modules (can-based, ...) are to expensive I
want to make my own remote-I/O module.
I need 10 inputs, 8 outputs and 4 analog outputs.
All digital I/O is 24V DC, the analog part 0-10V DC.
This will be used in a device that will be placed in a laboratory. So it
isn't really industrial but the module will sit next to 3 frequency
inverters (1/2 HP) and some contactors.
So, what kind of isolation should I use so that the module will keep on
working?
I was thinking of using an optocoupler (4N26) for the inputs and a
darlington driver (ULN2803) for the outputs (maybe in combination with small
PCB relais??).
The interface between PC and remote module will be RS232 and I'll also use
an optoisolated RS232 driver.
But what about the analog outputs? I have no idea what I'll need for that
(anyone knows a good chip with 8bits resolution?) or what I need for
isolation.
In fact, it makes me wonder...
Do I really need this kind of isolation? Sure, I do it for the digital
in -and outputs because it seems like the right thing to do.
Any insights?
Also, if anyone has used some I/O in an industrial place could you tell me
what parts you used, schematic, ...
Thanks,
Thierry
Because PCI-cards or remote-I/O modules (can-based, ...) are to expensive I
want to make my own remote-I/O module.
I need 10 inputs, 8 outputs and 4 analog outputs.
All digital I/O is 24V DC, the analog part 0-10V DC.
This will be used in a device that will be placed in a laboratory. So it
isn't really industrial but the module will sit next to 3 frequency
inverters (1/2 HP) and some contactors.
So, what kind of isolation should I use so that the module will keep on
working?
I was thinking of using an optocoupler (4N26) for the inputs and a
darlington driver (ULN2803) for the outputs (maybe in combination with small
PCB relais??).
The interface between PC and remote module will be RS232 and I'll also use
an optoisolated RS232 driver.
But what about the analog outputs? I have no idea what I'll need for that
(anyone knows a good chip with 8bits resolution?) or what I need for
isolation.
In fact, it makes me wonder...
Do I really need this kind of isolation? Sure, I do it for the digital
in -and outputs because it seems like the right thing to do.
Any insights?
Also, if anyone has used some I/O in an industrial place could you tell me
what parts you used, schematic, ...
Thanks,
Thierry
Comments
outputs also. I have driven 3010's in 6 pin dip package with a
series resistor to set stamp out current. I also use pull-downs
(duh!) I have switched Triac's, like the 2N6070 from the opto's
because these will switch a couple of amps w/o heatsink, meaning
that contactors and relays can be switched very reliably, millions
of times for maybe a buck apiece. The whole output circuit with two
more resistors and one cap is small, very inexpensive, yet very
reliable & heavy duty. I have used six at a time on BS2, up till
now, with no problems. If you think this may help, I'll be glad to
share more details.
What type of lab will your controller be used in?
Chris
ps: I have just visited with some friends from Brussels, and have
some equipment installed there. Are you near Brussels?
cl
Original Message
From: Thierry Vanmarcke [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=1tGKUjBWsJV9XOZikIe4n1nvT2_Zyrb0gwQz27zWXHur5YKoOaS1xfK3tKpg-n4bsc3xGhYCcg]tvm@p...[/url
Sent: Thursday, June 29, 2000 2:52 AM
To: basicstamps@egroups.com; picbasic-l@q...
Subject: [noparse][[/noparse]basicstamps] "Almost" industrial I/O
I need some interface to control 3 motors and read in some
switches.
Because PCI-cards or remote-I/O modules (can-based, ...) are
to expensive I
want to make my own remote-I/O module.
I need 10 inputs, 8 outputs and 4 analog outputs.
All digital I/O is 24V DC, the analog part 0-10V DC.
This will be used in a device that will be placed in a
laboratory. So it
isn't really industrial but the module will sit next to 3 frequency
inverters (1/2 HP) and some contactors.
So, what kind of isolation should I use so that the module will
keep on
working?
I was thinking of using an optocoupler (4N26) for the inputs and a
darlington driver (ULN2803) for the outputs (maybe in
combination with small
PCB relais??).
The interface between PC and remote module will be RS232 and
I'll also use
an optoisolated RS232 driver.
But what about the analog outputs? I have no idea what I'll
need for that
(anyone knows a good chip with 8bits resolution?) or what I need
for
isolation.
In fact, it makes me wonder...
Do I really need this kind of isolation? Sure, I do it for the
digital
in -and outputs because it seems like the right thing to do.
Any insights?
Also, if anyone has used some I/O in an industrial place could
you tell me
what parts you used, schematic, ...
Thanks,
Thierry
than $10.00 and they work great.
The ISO103 may be another option since it has its own internal isolated
power source.
Original Message
From: "Thierry Vanmarcke" <tvm@p...>
To: <basicstamps@egroups.com>; <picbasic-l@q...>
Sent: Thursday, June 29, 2000 2:51 AM
Subject: [noparse][[/noparse]basicstamps] "Almost" industrial I/O
> I need some interface to control 3 motors and read in some switches.
> Because PCI-cards or remote-I/O modules (can-based, ...) are to expensive
I
> want to make my own remote-I/O module.
> I need 10 inputs, 8 outputs and 4 analog outputs.
> All digital I/O is 24V DC, the analog part 0-10V DC.
> This will be used in a device that will be placed in a laboratory. So it
> isn't really industrial but the module will sit next to 3 frequency
> inverters (1/2 HP) and some contactors.
> So, what kind of isolation should I use so that the module will keep on
> working?
> I was thinking of using an optocoupler (4N26) for the inputs and a
> darlington driver (ULN2803) for the outputs (maybe in combination with
small
> PCB relais??).
> The interface between PC and remote module will be RS232 and I'll also use
> an optoisolated RS232 driver.
> But what about the analog outputs? I have no idea what I'll need for that
> (anyone knows a good chip with 8bits resolution?) or what I need for
> isolation.
> In fact, it makes me wonder...
> Do I really need this kind of isolation? Sure, I do it for the digital
> in -and outputs because it seems like the right thing to do.
>
> Any insights?
> Also, if anyone has used some I/O in an industrial place could you tell me
> what parts you used, schematic, ...
>
> Thanks,
> Thierry
>
>
>
>
>
>
> outputs also. I have driven 3010's in 6 pin dip package with a
> series resistor to set stamp out current. I also use pull-downs
> (duh!) I have switched Triac's, like the 2N6070 from the opto's
> because these will switch a couple of amps w/o heatsink, meaning
> that contactors and relays can be switched very reliably, millions
> of times for maybe a buck apiece. The whole output circuit with two
> more resistors and one cap is small, very inexpensive, yet very
> reliable & heavy duty. I have used six at a time on BS2, up till
> now, with no problems. If you think this may help, I'll be glad to
> share more details.
Please do so, I am very new to this stuff and every help is welcome ;-)
> What type of lab will your controller be used in?
Well, lab is a big word. It will be used in the lab of a potato processing
plant. I am designing an 'automatic length-analyzer' for french fries.
> ps: I have just visited with some friends from Brussels, and have
> some equipment installed there. Are you near Brussels?
Not really, I live in Kuurne (Kortrijk). But what is 'near'. By American
standards this is probably very near!
Thanks for the help so far.