Why can't I perform a TARE command?

1. Ensure you are monitoring the NET weight display and not the GROSS weight. The TARE register will be updated even though you are in the GROSS mode, it just won't shift to the NET weight display.

2. Verify the scale is not in motion by monitoring the motion bit or led on the front panel. You may not have allowed enough time for the weight to settle on the scale. Allow at least 1 second after the material has stopped flowing or moving. The unit must be out of motion (not moving) to allow a TARE function. Check to see if the weight on the scale is stable. Check the mechanics of your scale to ensure there is no motion. Check the motion tolerance setting. Motion Tolerance is usually set to the load cell capacity X 0.0003. For example, a 10K lb scale would have a Motion Tolerance setting of 3 lbs.  Or 3/10,000

3. For Remote Tare, verify you are making a good electrical connection between the terminal marks GND and the function you are requesting. (On the HI 2151/30WC, TARE is pin number one.) The screws need to be tight to allow contact.

4. Watch the scale display (or word location for the NET mode) for a weight change when the tare command is given.

5. Using the front TARE button, verify the TARE operation functions.

6. Note the Net weight and the motion indicators. If the scale is not stable and is in motion, the Tare operation cannot be performed. The problem could be a ground potential problem, a mechanical problem, or a defective load point. On the HI 2151/30WC Remote Functions connector, you can try installing a wire between pins 9 or 10 to the chassis shield screw.

7. If a Load Cell simulator is available, try using it to see if it eliminates the weight fluctuations.

8. Setting the unit back to factory defaults would verify if the problem is an internal logic problem.

Caution!!! Setting the instrument back to factory defaults requires a full calibration.