RS232 comunicaation doubt

Hi all
I have a Doubt with serial comunication. I need read and write data. The data for read comes for external hardaware(microcontroller), and data for write is for send to microcontroller. The read and write work very well separately, but when I want user the two in a single VI, no work well. I use a stacked sequence with 3 frames. one for read, one with a delay and the last for write.but No work well....
Can you help me?
I need know how use read and write

Other than what Raven's Fan has pointed out, I don't see anything either. You are intending to see a carriage return to terminate your received data, correct? This is how you have it set up.
Reese, (former CLAD, future CLD)
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I am about to commence a project which will require my LabVIEW application to communicate with an RS232 device. I am planning on using an Ethernet 4-slot Compact DAQ module, but can't see a way to connect through.
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So you mention you have a ethernet cDAQ. Would it then be possible to add an ethernet switch, and a Ethernet to Serial device? I have never used one but it appears that a quick google search finds lots of modules that can take ethernet from an RJ45 and convert it to RS232 in a DB9. Here are a few links.
http://www.perle.com/products/RS232-to-Ethernet.shtml
http://www.lantronix.com/device-networking/embedded-device-servers/xport.html
http://www.bb-elec.com/Products/Ethernet-Serial-Servers-Gateways/Ethernet-Serial-Device-Servers.aspx
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If 10 out of 10 experts in any field say something is bad, you should probably take their opinion seriously.

Desperate questios on RS232 Communication

Hallo all expert,
The attachment is a vi which is expected to write/read data to/from COM1 of my machine. For verification, I simply short circuited pin 2 and 3 of the RS232 port. However there are some questions following my experiment:
1. In the chart the label of x-axis can not be restored to be 0 to 100, it automatically increases without limits. I wish it start from 0 instead resuming a time instant;
2. In the "read string" field the display is not updated during my typing characters in "string to write", although I have enabled "Update Value while Typing";
3. The display in the chart doesn't correspond to what I have typed. Should I need more functions in order to show up the data?
My final purpose is to use this interface to communicate a pic chip which I programed to realize A/D conversion. At begin, a value is ought to be sent to the chip where the value is compared and if it is "1"f, then the conversion is initiated, and the value is read in the chart and could be also saved a excel file for documentation.
I'm wondering how to input value "1", instead string "1". I successfully type "Ctrl-A" in HyperTerminal, but have no idea which function is due to be used to realize the corresponding conversion.
Attachments:
myrs232r_r.vi ‏36 KB

There are several ways to send a hex 01 with the VISA Write, and all have been explained numerous times onn the forum. One wya is to simply right click on your string control/constant and select Hex Display. You can right click and select '\' Code Display and enter \01. You can have a numeric control and use the Byte Array to String. You can have a numeric control and use the Typecast function to convert to a string.
Your error can be due to the device not sending any data back, hence the VISA Read times out waiting for non-existant data. If you sometimes get data and are unsure of the length, you need to use VISA Bytes at Serial Port wired to the byte count input of VISA Read. This has also been discussed numerous times on the forum.
Message Edited by Dennis Knutson on 04-19-2007 06:15 AM
Attachments:
write hex to serial.PNG ‏4 KB

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Hello,

Sorry I am new posting a message here and I post it before I was able to describe my problem.
I have a Kollmorgen Servostar 300 to control an AKM24F motor and I would like to send the instructions to the controller via RS232 using LabView. I think I had achieved communication from a PC to a Servostar 300 using LabView via the serial port.
So far I have setup in LabView the configuration of the RS232 (8 bit, no parity, baud rate 38 400), the address of the servostar (ADDR 0), the way the servostar should respond to the host (PROMPT 1) and the error flag (MSG 1), and no error had been detected when I run the program. I should mentioned that after I sent an instruction such as ADDR 0 terminated with a carriage return, I set a delay time of 150 ms, then I read the amount of bytes that are in the buffer, and then I read the buffer, as I mentioned no error message has appear and the ADDR 0 instruction is read from the buffer. Following the same procedure I sent an instruction to move the motor but nothing happens.
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The output of a power supply in labview using a Magna Power LXI over RS232 to simulate a periodic voltage.

How can I toggle the output of a power supply in labview using a Magna Power LXI over RS232 to simulate a periodic voltage? Any help would be apreciated?

LXI is Ethernet communication.
Does the power supply have an RS232 port?
Are you looking for an RS232 to Ethernet (LXI) Converter
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=rs232%20to%20ethernet%20ip
But to simulate a periodic voltage you need to send the SCPI "Source" command to the power supply in a loop.
Changing the Voltage setting in periodic value.
How fast of a periodic voltage do you need?
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Use VISA writes. It is the same for LXI as it is for RS232. The LabVIEW code would be the same.
After you select the corrent VISA Ref, either a com port or an IP address, LabVIEW does not care if it is LXI or RS232.
From a Magna manual I found
Command Syntax
[SOURce]:VOLTage[:LEVel][:IMMediate][:AMPLitude] <nrf+>
[SOURce]:VOLTage[:LEVel]:TRIGgered[:AMPLitude] <nrf+>
Examples
VOLT 200
VOLTAGE:LEVEL 200
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Control Instrument using RS232 port

I have tried to download the IVI driver of the Agilent E3633A that stated can communicate using GPIB or Serial.
I tried to initialize the instrument but no successful.
I used a twisted ( tx and rx swap) RS232 cable (female to female) to connect between the instrument and PC com port.
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Hello,
Here's what you can do to verify that you have established communication with the instrument.
First gather the relevant information:
1. Find a command that you know your instrument "understands" (it is highly likely that it will understand *idn? which should prompt the instrument to reply with a description of itself).
2. Verify the serial settings that your instrument uses by default, such as baud rate, number of data bits (likely 8), parity, and the number of stop bits. You can also verify what termination character the instrument uses (which it likely does); this is the last character you will need to send after sending the relevant command characters, and it will indicate the end of the command to the instrument so that it stops reading from the serial port. I doubt that the instrument is configured for flow control of any kind by default, so don't worry about that unless there is specific indication of this in the manual for your instrument.
3. Verify the type of your cable; that is, you will need to connect pin 2 of your computer's COM port to pin 3 of your instrument's COM port, and pin 3 of your computer's COM port to pin 2 of your instrument's COM port. Some cables automatically switch these connections with the wires inside the cable, others are "straight through." You can bypass the cables altogether and just use wires to make the relevant connections initially; don't worry about a twisted pair at first, just keep the wires short and you should be ok (unless you are in a particularly noisy environment).
Now build the LabVIEW program:
1. Open a blank VI
2. Navigate to and pin down the following functions palette on the block diagram:
All Functions -> Instrument I/O -> Serial
3. Place onto the block diagram the four VIs/functions in the top row in the order they appear (should be VISA Configure Serial Port, VISA Write, VISA Read, VISA Close); note that the open will be performed implicitly the property node inside the VISA Configure Serial Port VI (don't worry about this).
4. Hover over the upper left hand terminal of the VISA Configure Serial Port VI, right click, and choose
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6. Wire the top right hand terminal to the top left hand terminal of adjacent VI's (which should be in the order noted above); this connects the resource name to each so they perform the operations on the chosen serial port
7. Wire the bottom left to the bottom right hand terminals in a similar fashion; this connects the error clusters
8. Almost done... now hover over the remaining left input of the VISA Write function (called write buffer), right click, and create a constant; type *idn? (and include a linefeed character at the end by typing the key)in the string constant that you just created
9. Similarly for the read function, create a constant for the input that indicates the number of bytes to read (perhaps make this number 100 as you will likely terminate the read appropriately when a termination character is read; your instrument will likely send this), and create an indicator for the "read buffer" output which will show you the string that is read back when you run the program.
10. You should now be able to run the program; hope it works.
I would have included a screenshot or example instead of a description, but I don't have access to that at this time and perhaps it is best to actually go through the process of building the VI anyway if you are new to LAbVIEW.
Good luck and repost if you continue to have troubles!
Thank you,
Best Regards,
JLS
Best,
JLS
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Hi,
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Hi..,
1)
See if u sort the table on a field on which u r using AT ENDAT .. then all the records which are having the same value for that field will form a group or those reocrds will be at one place.. so when u sort the table for all the records AT ENDAT will get executed onli once..
If u dont sort this table on this field then all these records will be at different places and in between there may be records with different value for this field.. so this AT ENDAT will get executed for each record !!
2)
No u cannot use the Right hand fields of the field in the table .. Because these AT events work as Group based operations... So till that field on which AT ENDAT is working it breaks that record into two groups.. One is the left hand fields including that field.. and right hand fields as another group.. and makes the right hand group as stars ****. Thats y u can observe that even any one field in the left hand group changes the AT ENDAT will get executed !!!!
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RS232 comunicaat​ion doubt

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RS232 comunicaation doubt