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Discussion Groups | Rabbit-Semi | Mulitple serial
This is a group for folks designing and programming embedded systems using the Rabbit Semiconductor C-programmable microcontroller. Rabbit Semi is a spin-off from Z-World who makes a variety of embedded modules and tools. This group is not affiliated with either Rabbit or Z-World, but is a user forum for sharing ideas, asking questions, flaunting knowledge, and other typical user group stuff. The Rabbit is a powerful uC, supported by a full-featured C-compiler.
Mulitple serial - jackd053 - May 21 19:36:42 2008
I am working on a project that needs to manage 3 serial ports. One is a
Modbus port, one communicates with a piece of equipment to monitor
status and the other needs to simulate a temperature transmitter. The
temp transmitter must respond very quickly (on the order of 75-100 ms,
but I do not have a spec on the actual timeout) once the request for
data is sent. Any miss causes the equipment attached to the transmitter
to fail. I attempted using costate and cofunctions but the timing is
too close to the limit and I get an occasional failure. I was thinking
of writing an ISR for the temp transmitter or FSM. Neither of these are
going to be an easy task. Does anyone have any idea as to a good method
to handle the tight timing requirements? The timing requirements for
the other two ports is not critical.
------------------------------------
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Modbus port, one communicates with a piece of equipment to monitor
status and the other needs to simulate a temperature transmitter. The
temp transmitter must respond very quickly (on the order of 75-100 ms,
but I do not have a spec on the actual timeout) once the request for
data is sent. Any miss causes the equipment attached to the transmitter
to fail. I attempted using costate and cofunctions but the timing is
too close to the limit and I get an occasional failure. I was thinking
of writing an ISR for the temp transmitter or FSM. Neither of these are
going to be an easy task. Does anyone have any idea as to a good method
to handle the tight timing requirements? The timing requirements for
the other two ports is not critical.
------------------------------------
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RE: Mulitple serial - Nathan Johnston - May 21 20:22:38 2008
You could look at using an ISR, but another approach would be to use an
RTOS (i.e. uCOS||) and have the temperature transmitter interface
controlled in a high priority task. I did a previously project where all
6 serial ports had strict timing constraints and uCOSII worked very well
in handling this.
Regards,
Nathan
-----Original Message-----
From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
On Behalf Of jackd053
Sent: Thursday, 22 May 2008 9:36 AM
To: r...@yahoogroups.com
Subject: [rabbit-semi] Mulitple serial
I am working on a project that needs to manage 3 serial ports. One is a
Modbus port, one communicates with a piece of equipment to monitor
status and the other needs to simulate a temperature transmitter. The
temp transmitter must respond very quickly (on the order of 75-100 ms,
but I do not have a spec on the actual timeout) once the request for
data is sent. Any miss causes the equipment attached to the transmitter
to fail. I attempted using costate and cofunctions but the timing is
too close to the limit and I get an occasional failure. I was thinking
of writing an ISR for the temp transmitter or FSM. Neither of these are
going to be an easy task. Does anyone have any idea as to a good method
to handle the tight timing requirements? The timing requirements for
the other two ports is not critical.
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
RTOS (i.e. uCOS||) and have the temperature transmitter interface
controlled in a high priority task. I did a previously project where all
6 serial ports had strict timing constraints and uCOSII worked very well
in handling this.
Regards,
Nathan
-----Original Message-----
From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
On Behalf Of jackd053
Sent: Thursday, 22 May 2008 9:36 AM
To: r...@yahoogroups.com
Subject: [rabbit-semi] Mulitple serial
I am working on a project that needs to manage 3 serial ports. One is a
Modbus port, one communicates with a piece of equipment to monitor
status and the other needs to simulate a temperature transmitter. The
temp transmitter must respond very quickly (on the order of 75-100 ms,
but I do not have a spec on the actual timeout) once the request for
data is sent. Any miss causes the equipment attached to the transmitter
to fail. I attempted using costate and cofunctions but the timing is
too close to the limit and I get an occasional failure. I was thinking
of writing an ISR for the temp transmitter or FSM. Neither of these are
going to be an easy task. Does anyone have any idea as to a good method
to handle the tight timing requirements? The timing requirements for
the other two ports is not critical.
(You need to be a member of rabbit-semi -- send a blank email to rabbit-semi-subscribe@yahoogroups.com )
Re: Mulitple serial - jackd053 - May 21 20:37:24 2008
Good point. Have you used uCOSII with the Rabbit Modbus module? I
appreciate the help.
Jack
--- In r...@yahoogroups.com, "Nathan Johnston"
>
> You could look at using an ISR, but another approach would be to use
an
> RTOS (i.e. uCOS||) and have the temperature transmitter interface
> controlled in a high priority task. I did a previously project where
all
> 6 serial ports had strict timing constraints and uCOSII worked very
well
> in handling this.
>
> Regards,
>
> Nathan
>
> -----Original Message-----
> From: r...@yahoogroups.com [mailto:r...@yahoogroups.com]
> On Behalf Of jackd053
> Sent: Thursday, 22 May 2008 9:36 AM
> To: r...@yahoogroups.com
> Subject: [rabbit-semi] Mulitple serial
>
> I am working on a project that needs to manage 3 serial ports. One is
a
> Modbus port, one communicates with a piece of equipment to monitor
> status and the other needs to simulate a temperature transmitter. The
> temp transmitter must respond very quickly (on the order of 75-100 ms,
> but I do not have a spec on the actual timeout) once the request for
> data is sent. Any miss causes the equipment attached to the
transmitter
> to fail. I attempted using costate and cofunctions but the timing is
> too close to the limit and I get an occasional failure. I was thinking
> of writing an ISR for the temp transmitter or FSM. Neither of these
are
> going to be an easy task. Does anyone have any idea as to a good
method
> to handle the tight timing requirements? The timing requirements for
> the other two ports is not critical.
>
------------------------------------
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