Problem with Comport RS232 Send

[Megan]

I've run into an issue with the setup of a com port that I'm using to communicate with an RS232 flow meter. I can receive data from the flow meter via FlowStone using 13 (carriage return) as my RxTerminator. The problem is that when I try to send using the same com port setup, I get no return response from the flow meter. I know that the flow meter is looking for a carriage return to execute a command (A<CR>, for example, would read the flow at meter A), so I'm assuming that this is an issue with the carriage return bit, but I'm new to FlowStone and I'm not sure what's going on. I've tried 'A<CR>' and 'A' in the Data String to send, but neither works. I also tried removing the RxTerminator all together but that did not work either. Any suggestions on how I might approach this? Unfortunately the flow meter does not allow the user to change the line terminating character to anything other than a carriage return.

[acg2010]

@Megan
I had a similar problem with the RS232 Comport communication in my On-Board Diagnostic (OBD-II) vehicle project. It had to do with sending the line terminus as string or ASCII as I recall. The discussion is here if you want to read and see if any of it helps. As I only have the free version of Flowstone, I can't check your schematic. Good luck with your project.

viewtopic.php?f=2&t=2886&p=15568#p15568

viewtopic.php?f=72&t=2934

-acg2010

[Megan]

Thanks very much, it looks like that was the problem after all. I translated the command sent to the flow meter to hex and set the 'Hex' option to 'true' on the comport. The output then came out as hex so I just added an object to convert it back to an ascii string, works like a charm.

[acg2010]

Glad you got it sorted out. This website has some great information on logging and connection of sensors and measurement equipment as well as some good software tools for com port debugging/communications:

http://www.windmill.co.uk/