Answer
There are two different ways to run your basic commands, like Tare, Zero, Calibrate Low, Cal High, or C2 Cal.
By placing the command value into the Output table.
By running the MSG instruction.
The differences between these two methods is:
The first method will give you a bit in the Statusword to indicate pass or fail. It will not give you a specific error code.
The second method will give you back a specific return code in the return that indicates cmd passed or what condition caused the command to fail.
During normal operation, there are only a few conditions that will cause the tare command to fail. These are, A/D error, A/D failure, and Motion. You should be able to condition your rung with checks of these conditions so the tare command is not sent unless there are no conditions present that would cause it to fail.
The Zero command will have the same possible conditions as the tare command, but will also have the limitation of being within the zero tolerance setting. In this case, if you condition the rung with the above conditions, then if the zero command fails, it could only be due to being out of tolerance. This way, you do not necessarily need the actual error code, since there is only one reason beyond those conditions already checked for.
The calibration commands have the same limitations as the tare command, but you would need to insure that:
If you are doing a C2 calibration, that you have C2 load cells attached. Otherwise it will fail.
If you are doing the Cal High command, you must place weight on the scale to cause the input signal to increase above what the input at Cal Low was.
There are some commands that take time to complete. During these commands, the module will stop updating the weights. This is normal. This may appear as if being “disabled”. Whereas when I think “disabled”, I think the channel has had the channel active parameter set to off, thus actually turning the channel off. In this second case, the scale led will also go off.
