Interfacing two devices using RS-232 ports

[[email protected]]

Hi. I need to interface two devices, both offering a RS-232 port. The
general idea is to read the output (weight) from an electronic scale
using it's RS-232 port, compose a string (containing control codes and
the message to be printed) and send the string to an industrial ink-jet
printer. We are talking about 1 reading/printing per minute. Follows
a simple block diagram:

|----------------------|
Scale -> | Protocol converter | -> Ink-jet system
|----------------------|
^
|
Product sensor

I am borrowing the "protocol converter" concept from a product named
PPC (Programmable Protocol Converter,
http://www.kksystems.com/english/html_files/product_pages/ppc.htm) form
KK Systems.

Assuming that I have both the scale and printer techincal information
(that is, their protocol definition), I request your comments to
determine good options for the "protocol converter" system. "Good"
refers to simple and economical yet robust solutions since this is
intended for use in an industrial environment.

So far I have found the KK product mentioned before, and I am also
considering using a low power (both in terms of power consumption and
processing power) PC/104 solution.

As you might have already guessed, reading the output (I am considering
a few 10-20 bytes long per scale reading) and generating the string
(which should be around 20-30 characters long including the scale
reading) at one per minute does not require a superscalar processor
A 25 MHz processor should be more than enough, I am considering this
speed because is the smallest systems I have found so far.

For your ideas, thanks in advance.

 

[Art]

[email protected] wrote in @g44g2000cwa.googlegroups.com:

Hi. I need to interface two devices, both offering a RS-232 port. The
general idea is to read the output (weight) from an electronic scale
using it's RS-232 port, compose a string (containing control codes and
the message to be printed) and send the string to an industrial ink-jet
printer. We are talking about 1 reading/printing per minute. Follows
a simple block diagram:

|----------------------|
Scale -> | Protocol converter | -> Ink-jet system
|----------------------|
^
|
Product sensor

I am borrowing the "protocol converter" concept from a product named
PPC (Programmable Protocol Converter,
http://www.kksystems.com/english/html_files/product_pages/ppc.htm) form
KK Systems.

Assuming that I have both the scale and printer techincal information
(that is, their protocol definition), I request your comments to
determine good options for the "protocol converter" system. "Good"
refers to simple and economical yet robust solutions since this is
intended for use in an industrial environment.

So far I have found the KK product mentioned before, and I am also
considering using a low power (both in terms of power consumption and
processing power) PC/104 solution.

As you might have already guessed, reading the output (I am considering
a few 10-20 bytes long per scale reading) and generating the string
(which should be around 20-30 characters long including the scale
reading) at one per minute does not require a superscalar processor
A 25 MHz processor should be more than enough, I am considering this
speed because is the smallest systems I have found so far.

For your ideas, thanks in advance.

try jkmicro.com
they have range of inexpensive embedded DOS boards for as low as $69 with
3 serial ports (Flahslite186). Dev kit with Borland C++ is only $99. I
use them in number of my projects, good service.
arthur
klocworx AT shaw DOT ca

 

[Rune Christensen]

Hi. I need to interface two devices, both offering a RS-232 port. The
general idea is to read the output (weight) from an electronic scale
using it's RS-232 port, compose a string (containing control codes and
the message to be printed) and send the string to an industrial ink-jet
printer. We are talking about 1 reading/printing per minute. Follows
a simple block diagram:

|----------------------|
Scale -> | Protocol converter | -> Ink-jet system
|----------------------|
^
|
Product sensor

I am borrowing the "protocol converter" concept from a product named
PPC (Programmable Protocol Converter,
http://www.kksystems.com/english/html_files/product_pages/ppc.htm) form
KK Systems.

Assuming that I have both the scale and printer techincal information
(that is, their protocol definition), I request your comments to
determine good options for the "protocol converter" system. "Good"
refers to simple and economical yet robust solutions since this is
intended for use in an industrial environment.

So far I have found the KK product mentioned before, and I am also
considering using a low power (both in terms of power consumption and
processing power) PC/104 solution.

As you might have already guessed, reading the output (I am considering
a few 10-20 bytes long per scale reading) and generating the string
(which should be around 20-30 characters long including the scale
reading) at one per minute does not require a superscalar processor
A 25 MHz processor should be more than enough, I am considering this
speed because is the smallest systems I have found so far.

For your ideas, thanks in advance.

Even a small MCU should be able to convert the string into something on
paper. Just look after something with two rs-232 ports.

Rune Christensen
M.Sc.E.E.