point IO 1734-232ASC help (rs232)

Can anyone please help me, im trying to communicate with an RS232 device 9 a conductivity meter (SIGMATEST 2.069) using a point IO 1734-232ASC.

I can write a string to the device, but i cant listen to the response.
The AB manual (point i/o ascii modules) says the module needs to be in monitoring mode, but i cannot find how to activate this. any ideas?

I can successfully communicate with the conductivity meter using hyper terminal (both transmit and relieve)
I have also tried connecting my PC's rs232 terminal to the point io, and write strings using hyper terminal, but the module still wont listen.

Any ideas would be great

Gareth

You have already tried hyperterminal, which is the first thing I would suggest. The other thing I would try, is going online with the PLC and looking at the Status bits of the 1734-232ASC module. This manual should have more info:

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1734-um009_-en-p.pdf

outside of hyperterminal, I'd suggest Docklight


https://docklight.de/

gareth_mint said:

Can anyone please help me, im trying to communicate with an RS232 device 9 a conductivity meter (SIGMATEST 2.069) using a point IO 1734-232ASC.

I can write a string to the device, but i cant listen to the response.
The AB manual (point i/o ascii modules) says the module needs to be in monitoring mode, but i cannot find how to activate this. any ideas?

I can successfully communicate with the conductivity meter using hyper terminal (both transmit and relieve)
I have also tried connecting my PC's rs232 terminal to the point io, and write strings using hyper terminal, but the module still wont listen.

Any ideas would be great

Gareth

Click to expand...

I have no experience with this particular module, just looking at the same manual you have.

Are you waiting for a specific number of characters (receive buffer full) or an end of string character?

And what does your meter send as data when you have it connected in hyperterminal?

If it sends a carriage return and line feed, then you can use the CR (decimal 13) or the line feed (decimal 10) to signal that the meter is done sending you data.

Since you have the ascii module sending data, you will have your receive buffer size defined.

For a quick test, connect hyperterminal to your ascii module and just send 132 X's .. I think 132 is the maximum string length from the manual. Heck, send 150 X's. No matter what else, the module should return the string full of X's when the buffer is full.

That should show you that it works at all. Then you can mess around with figuring out if there is a start character and an end character in your meter's data stream that will work with the module. You have data from your hyperterminal session with the meter, so you will figure it out.

A_G said:

You have already tried hyperterminal, which is the first thing I would suggest. The other thing I would try, is going online with the PLC and looking at the Status bits of the 1734-232ASC module. This manual should have more info:

https://literature.rockwellautomation.com/idc/groups/literature/documents/um/1734-um009_-en-p.pdf

Click to expand...

thank you, i cannot get the statud bit to change and im trying to overflow the buffer

i will try as you say now,
thank you

Gareth

very simple in the end, i was missing a <cr>

thanks for the help
Gareth

gareth_mint said:

very simple in the end, i was missing a <cr>

thanks for the help
Gareth

Click to expand...

So you were able to get it working in Hyperterminal.

Did you get the meter to add the <CR> at the end of the message?

Thanks for letting us know

I had a go at using docklight and as this shows the cr as a symbol on the end of the reply from the node, I could see straight away where I was going wrong and what I needed to do in the settings.