LINK Systems OmniLink 5000 - Manual (Page 71)

April 17, 2000 Man ual Revisio n 1.0
8.3
Note that the machine rating must be set correctly before calibration and not changed
afterward. Changing the machine rating number after calibration will result in erroneous
tonnage readings.
Section 8.1 Dynamic Calibration with Load Cells
a) Check to see that the OmniLink 5000 Tonnage Monitor Module is installed as per the installation
instructions of this manual.
b) Turn on the power to the OmniLink 5000. Observe that the OmniLink 5000 tonnage monitor
module displays zero. If the tonnage displays fail to zero within 40 seconds or an error occurs, check
that the strain gauges are wired correctly into the channel connectors and refer to error conditions
listed in this manual.
c) Before calibration can proceed, verify that all configuration parameters are properly set.
If error conditions relating to setpoint limits occur, correct the invalid conditions and press the
RESET ERROR softkey.
d) Set the high setpoint for each channel of the installed OmniLink 5000 Tonnage Monitor Module to
about 10% greater than the tonnage expected on each channel when the machine is loaded at rated
tonnage. The expected tonnage for a two channel tonnage monitor at full load is one-half (½) the
rated tonnage of the machine. For a four channel module, the expected tonnage for each channel is
one-fourth (1/4) the rated tonnage of the machine.
Example: A machine is rated at 200 tons. The high setpoint limits for each channel should be set to
110 tons (10% over ½ of 200 tons) for a two channel tonnage monitor module, or 55 tons (10% over
1/4 of 200 tons) if a four channel module is installed.
e) Set the low limits for each channel to Zero (0).
f) Set the reverse limits for each channel to -10% of channel rating.
g) Bring the machine slide or ram to the bottom of stroke position and turn off power to the machine.
Place the load cell(s) to be used for calibration into position in the machine. Load cell(s) of similar
capacity and dimension are preferably centered under each drive connection to the slide or ram of the
machine. Also place any parallels or similar thickness plates on or under the load cells necessary to
reduce the gap between slide and bolster (etc.) so that the "stack" of load cells and parallels can be
contacted at the bottom of the machine stroke.
It is recommended that steel plates at least one inch thick and of at least 2 inches greater lateral
dimension than load cell contact surfaces be placed both under and over the load cell to help
distribute load and avoid load cell impressions in slide or bolster material. All plates or parallels
should be symmetrically placed relative to the centerline of the load cells, and plates and parallels
used for each load cell stack should be similar in dimension to those used in other stacks.