Instrument Control (GPIB, Serial, VISA, IVI)
Communicating with load cell using virtual serial port
Solved!
Hello! I am trying to read from my load cell using VISA write and read. Below is my vi. The load cell is using ASCII protocol. I have suceeded using Hyperterminal to communicate to my load cell, but I can't get it working in Labview with exactly the same settings and command. Does anyone know what's the problem here? Thanks!
You are not to send "<CR>". That is supposed to be a single character: a Carriage Return (ASCII value of 13, 0xD). This might be the case where using the ASRL End Out property would be very useful. Set that property to Termination Character and the Carriage Return will be appended for you by the VISA driver.
Put down a property node and wire up the VISA resource to the reference. Click on the property and choose Serial Settings->End Mode for Writes.
Due note that this property is only valid for serial ports. I don't normally recommend this route because I work with instruments that can also communicate over GPIB, Ethernet, and/or USB. So I usually use Concatenate String and a Carriage Return Constant to add the CR and then wire that result to the VISA Write.
@stargazerl wrote:
So the problem was that the end of commands were not sent correctly? And how does ASRL End Out solve this problem?
1. Correct. You were sending 4 characters that the device has no clue what to do with ("<CR>"). What the device really wanted was a single character.
2. As I stated before, this property tells the VISA driver to append the termination character, in this case the Carriage Return, whenever a write is performed. So the driver is handling the termination character for you once it is initialized.
