Transmit data with MAX232 using Labview.

[acro]

Currently, both transmitter and receiver is programmed using Basicstamp2.

Now I have to change the transmitter programming. Instead of using Basicstamp, I'm using a MAX232 circuit to transmit data to the receiver (which still uses BS2). I have to use Labview to transmit data ti the BS2 receiver. How do I go about doing it.

[Pnt]

You need to use the VISA functions.

There are a lot of threads with examples and info. Trere are examples at Labview examples too.

Do a little search and ask if you have further questions

[Ray.R]

Go under the Help menu and select Find Examples.

Then do a search for "serial".  It will find several examples.  Look at the block diagrams of the examples to give you an idea how it is implemented.

R

[acro]

Thank you for your suggestions.

I'm now testing out the MAX 232 circuit using the Basic Serial Write and Read.vi.

I tried testing it with loopback (pin 2 and 3 of DB9 shorted) with 5V power supply. When I run the vi, the 'read string' did not match the 'string to write'.

However, without 5V power supply, the 'read string' did match the 'string to write'.

Does it need a 5V power supply for it to work?

If it does, how come it didn't match?

Regards,
acro

[Pnt]

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acro wrote:
However, without 5V power supply, the 'read string' did match the 'string to write'.

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Matches because you have the max232 off, and the short circuit is before max232

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acro wrote:
I tried testing it with loopback (pin 2 and 3 of DB9 shorted) with 5V power supply. When I run the vi, the 'read string' did not match the 'string to write'.

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Does not work because you should short circuit the pins after the MAX232 (5V logic)

[acro]

Thank you PNT for your comments.

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@Pnt wrote:

Does not work because you should short circuit the pins after the MAX232 (5V logic)

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What do you mean by 'short circuit the pins after the MAX232'?

[Pnt]

In which pins of MAX232, do you connect the pin 2 and 3 of DB9 ?

[acro]

Pin 2 and 3 are connected to Pin 14 and 13 of MAX232 IC respectively.

I tried to short pin 14 and 13 (MAX232) but it's still the same thing as shorting pin 2 and 3 (DB9).

Regards,
acro.

[Pnt]

Short circuit pins 11, 12.

Look at page 7 of max232 datasheet.

Those on left have 5V logic. Those on right, have higher volt logic (rs232)