Serial modem communication

...so my boss found out that I USED to do some hobby programming in Borlands C++ BUILDER years ago and he thinks that makes me the resident programming "expert". He bought LabVIEW and despite the fact that I've never seen it before he tossed it to me and said "'you da man!"...
He's ordered device that connects multiple monitoring instruments to a serial port. He want me to produce a app that'll eventually grab the data it logs and save it to a file. Sounds pretty easy ---
To begin I connected a modem as a device to test with and made sure I could talk to it via AT commands with HyperTerminal. I've spent considerable time since trying to cook something up to communicate with no luck - and then tried lvterm.vi (found it here). I'm hoping it'll give me some insight and I can mod it as needed.
LVTerm seems to allow me to set the port parameters get an echo of what I type but I can't get the typical responses to the AT commands (followed with /r/n). I can see my modems Rx & Tx light blink - but that's all.
I've never played with apps that work with ports (even in C++)....anyone have any tips or references that might help? LabVIEW seems pretty robust with regard to this sort of thing so it can't be too tough.
thanks -
(Soon to retire) US Coast Guard CPO
Solved!
Go to Solution.

I can send successfully send AT commands to the modem via Hyperterminal. For example, sending ATH0 or ATH1 will take the modem on / off hook. AT&VI will display the data stored in the various registers.
Attached is a .vi that I found on the forums here that I think would serve as a base for what I want to do with LV. It's similar to what I came up with on my own so I don't feel too bad about using it - especially since the author said it worked well for him. With it I can send (for example) ATH1/R/N or ATH0/R/N and take the modem on/off hook. I got success with this late last night after whining about having the trouble I've had.
-BUT-
I don't get the verbose responses - or even the typical "OK" after sending a valid command like I do with Hyperterminal. Should I? Maybe the issue is my not understanding what to expect. I do get the original command I sent w/o the "/r/n" suffix . I also do sometimes get framing errors to queries which tells me that baud/bits/parity might be incorrect, but since I can control the hook relay I assume that the modem and I are seeing eye to eye on parameters. Framing issues also indicate to me that there's some sort of data on the line from the modem. Summary is that I don't know if there data is there and I'm not accommodating it or if there's nothing there at all.
I get similar results with the various serial examples that ship with LV.
I figure that if I can see the verbose text responses from the modem I'll be able to do the same with other equipment that connect via a serial port and send data in response to particular commands.
Thanks
Jerry
(in Maine - where the leaves are just fixin' to change into their autum colors)
(Soon to retire) US Coast Guard CPO
Attachments:
serial.PNG ‏16 KB

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Solved!
Go to Solution.

Are you monitoring the using PortMon software ? Only thing I can see here is that check the command what you send, there might be some space which you might have introduced while typing,
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As i wrote that i have got the idea of 16 bit communication from the thread http://forums.ni.com/t5/LabVIEW/16-bit-receive-over-rs-232/td-p/1214869/page/3
The Code of this is also the same which is as under
Spoiler (Highlight to read)
Spoiler (Highlight to read)
The Data is transmitted as two serial bits and joined at the end. Wel can you give me a more clear idea of what could be the easy technique of specifying the start bit and stop bits.
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I am working on configuring communications Router to Router through serial port. I have seen some videos and read some documentations. My configuration is as follows:
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============================================
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Request timed out.
Request timed out.
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=====================================================
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Serial port communication problems

Hello. I am trying to control a MKS Instruments 651C Pressure Controller via RS-232. Right now, I am just trying to establish basic communication with the device over the serial port. I can connect to the device with windows hyperterminal using the following settings:
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Solved!
Go to Solution.

Have you tried running NI-Spy to see what is actually happening on the serial port? This may help you narrow down what is happening. I also wonder if you are having an issue since you are using 8-bit ASCII when you open the port but in hyperterminal you are telling it to use 7-bit ASCII to read the data.
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Basic serial port communication

Hi-
I am trying to use javax.comm API to transmit a byte array to a RS232 port (COM2) which is connected to an RF transmitter for wireless communication (the program just outputs the array, and doesn't recieive anything), and unfortunately a) I'm using windows, so i'm using the 2.0 API as opposed to the 3.0, and b) I have absolutely no I/O experience, so I'm grasping at straws at the moment and googling for possible examples. Any help/leads in the right direction? Thanks :)
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