06-13-2012 04:43 PM
Hello,
I'm relative new to LabVIEW and I'm trying to write a simple program to control (read) the temperatures from a Fluke Thermometer 1504 model. I have attached the thermometer's manual. The protocol for the manual is a bit confusing. I was wondering if someone could give me some pointers or provide me some resources to where can I start so I can get it going.
Thank you so much
06-13-2012 08:17 PM
@LVNewbie85 wrote:
Hello,
I'm relative new to LabVIEW and I'm trying to write a simple program to control (read) the temperatures from a Fluke Thermometer 1504 model. I have attached the thermometer's manual. The protocol for the manual is a bit confusing. I was wondering if someone could give me some pointers or provide me some resources to where can I start so I can get it going.
Thank you so much
Exactly what is "confusing" about the "protocol for the manual"?
I don't find it confusing. Very clear what the commands are and what they do.
06-13-2012 10:49 PM
06-14-2012 09:46 AM
The manual also says the device uses hardware handshaking. Make sure you set that up in the configuration and that your cable includes the handshaking wiring.
Lynn
06-14-2012 03:16 PM
Thanks for the tips Lynn and Dennis. With further reading, I understand a little bit better now. the handshaking is RTS/CTS. I will try to use the serial read and write.vi in example with some modifications first to see if it works. If I run into some problems then I'll ask you guys in the near future.
Again I'm very new to LabView so if my questions come across as dumb or whatever, then I'm sorry. Otherwise, I wouldn't come here asking questions 🙂
06-27-2012 11:11 AM
Hi Dennis,
So I tried to test it out using Basic Serial Write and Read.vi in LabView examples. By setting baud rate to 9600 which match what was set on the instrument, 8 data bits, no parity bit, 1 stop bit, RTS/CTS handshake, LF was set ON on the instrument. Then I tried to send a command T\n which I would expect to get some value on the read indicator. However, I only received "T". Do you have any suggestions?
Thank you
Tim
06-27-2012 11:18 AM
Did you disable the full duplex mode that echoes the commands back? Did you try doing a read without a write after getting the command echoed back?
06-27-2012 12:16 PM
Did you disable the full duplex mode that echoes the commands back? I tried to set the instrument to Half Duplex first which would not give out any reading, then I tried Full Duplex which would give the same string as the input command
Did you try doing a read without a write after getting the command echoed back? I'm not quite sure what you meant by that but the VI I have not modified anything yet from the VI example as attached
Thanks for your quick reply
06-27-2012 12:57 PM
It's actually very simple. In full duplex mode, you get the command echoed back and the read will automatically terminate because the VISA Read is set to stop when the termination character is detected (i.e. after T\r). Even if the instrument is also returning a reading, the VI will not see those additional bytes. If you run the VI and tell it to write the T and you do see the command echoed back, then run the VI again with the Write switch set to 'OFF'. That will force another read without sending the T again. If you don't see any results returned, then there is something else wrong. I would then suggest testing communication with a terminal emulation program such as hyperterminal, putty, etc.
06-27-2012 01:30 PM
Ok so I installed and used putty which give the reading just fine, so presumably the communication between the instrument and computer is established. I tried to do what you desribed and nothing returned...