Digital mass flow controller communicate with RS232

[wanman]

I have some problem with communication between digital mass flow controller(DMFC) and RS232 by using LabVIEW 8.0 to send the serial command in which there is no feedback from the device(DMFC). A serial command comprises of 8 digits ASCII; for example, @01RID80\r.  This command is used to ask th device I.D. where the first digit is started text(@), the next two digits are device I.D., then following with three ASCII code which is a command and finally, the checksum(Hex) and carriage return are at the end. In addition, I already checked all configulations of serial port and cable connection, but there are nothing wrong. Do you have any idea? 

Thank you

[Dennis_Knutson]

If you get no data, first check that the checksum is correct and that you are actually sending the carriage return character and not the strings '\' and 'r'. In order to send CR, your string control\constant should be set for '\' Code Display. You should also test the command in a program such as Hyperterminal. If it works there, then you know you have a problem with how you wrote the LabVIEW code. If it doesn't work in Hyperterminal, then there is something else wrong.

[NathanT]

Hello Wanman,
    What is the model and manufacturer of your DMFC?  There might already be a LabVIEW Plug and Play instrument driver for it on IDNet.

Cheers,

NathanT

[wanman]

Hi NathanT,

The  model of DMFC is 8300 series from KOFLOC( kojima, Japan). After checking all parts of the system(USB to RS232,RS232 wiring,command), I still can't communicate with them(no response). However, thank you for your suggestion; I will try.

Regards,

Wanman

[wanman]

Hi all,

Could someone plase check this!, I am wrong or right for writing the code in LabVIEW?  The serial command communication is @01RID80\r(set the string control\constant to '\' Code Display) where @ is started text, 01 is device I.D., RID is a command for reading the I.D., 80 is a low 8 bit order of checksum that summed from started text(@) to command(RID) (@(=40)+0(=30)+1(=31)+R(=52)+I(49)+D(=44)=0180(hex)) and \r.

Thank you

Regards,

Wanman

[Dennis_Knutson]

Did you in fact do any testing with Hyperterminal? I'll repeat what I already said. The only way to know whether there is a problem with your LabVIEW program is to determine whether the exact same command works someplace else.

If you have an electronic copy of the instrument manual (or a link to one), you could also post that. Someone might see a problem. for example, are you sure you have to add the byte values and not do a xor?

[wanman]

Hi Dennis,

Yes, I did it by sending the command "@01RID80\r" from LabVIEW to HyperTerminal(same computer with two RS232); the result shows that the command "@01RID80" appeared on HyperTerminal screeen. This means that there was no problem with LabVIEW. Here is an instrument manual http://www.tempf.com/getfile.php?filekey=1202528108.61049_view.pdf&mime=application/pdf 

Thanks

Wanman.

[wanman]

Again, here is the instrument manual http://www.yourfilelink.com/get.php?fid=457462

Thanks

[Albert.Geven]

Hi Dennis meant to communicate from hyperterminal with your instrument.
You only proved that the connection from your pc to pc is correct, maybe the instrument needs a cross over cable other a straight cabling
Also the handshake type can be wrong.

[wanman]

I already tried as you suggested, but there was no result because HyperTerminal transmits the data in form of character by character, which is not a set of serial command.