LINK Systems OmniLink II Press Automation Control - Manual (Page 68)

August 30, 2002 Manual Version 1.0 4.19
6. Observe the Stroke Speed indicator at the top of the operator terminal display. This is the true
stroking speed derived from RPM that the crankshaft turns in Continuous stroking. If the SPM
indicated is less than the Maximum SPM for the press, successively enter larger Output SPM Cal
numbers until either the highest Cal # of 4095 is reached without producing the Maximum SPM, or
until a Cal # lower than 4095 produces the maximum stroking speed. If a Cal # of 4095 produces a
stroking speed less than the specified maximum stroking speed of the press, follow the variable
speed drive manufacturer’s instructions and adjust the drive speed until it reaches maximum stroking
speed with the 10Vdc signal produced by the Cal # of 4095. If a Cal # lower than 4095 causes the
stroking speed to reach the specified maximum SPM, do not continue to increase the Cal #. Rather,
adjust the drive speed downward until well below the Maximum SPM and then begin to increase the
Cal # till 4095 is reached without exceeding maximum SPM. If necessary, re-adjust the drive speed
upward to the maximum SPM after the Cal # is set to 4095, its maximum value. Once this step is
complete, a Cal # of 4095 (and an analog voltage of 10Vdc) represents the highest stroking speed of
the press. Leave the press stroking, do not exit calibration mode, and proceed to step 7.
7. Next, the Cal # that will produce the minimum stroking speed of the press must be found. A first
approximation of this Cal # may be derived by assuming (as is usually the case) that the drive speed
input responds in a fairly linear fashion to the analog voltage that the Cal # determines. For
example, if a variable speed press is intended to stroke from a low of 50 SPM to a high of 150 SPM
and the drive is adjusted to produce 150 SPM at a Cal # of 4095 in step 6, a first approximation of
the Cal # that would produce 50 SPM , which is 1/3 of 150 SPM, would be 1/3 of 4095, or 1365.
Enter this number into the popup Output Cal # entry box at the bottom of the screen. The stroking
speed should slow down. Observe the Stroke Speed indicator at the top of the operator terminal
display until the speed has stabilized at the lower value determined by the Cal # entered. If the SPM
is lower or higher than the minimum stroking speed of the press, increase or decrease the Cal # until
the specified minimum stroking speed is reached. Once the correct Cal # is determined by entry into
the popup Cal # box, use the arrow keys to highlight the Minimum Output Cal # setting on the menu
and enter this number. Leave the press stroking, do not exit calibration mode, and proceed to step 8.
8. The Mid Range Output SPM and Mid Range Output Cal # settings are provided to linearize the press
speed with respect to the analog input when needed. Typically dc and variable frequency drives
exhibit linear characteristics and it is not necessary to set a mid range parameter. However, eddy
current drives can exhibit nonlinear behavior. To test for linearity, add the setting for Minimum
Output Cal # to 4095 and divide by 2. Enter this value into the popup Output Cal # entry box at the
bottom of the screen. The Stroke Speed indicator at the top of the operator terminal display should
display a stroking speed halfway between the minimum and the maximum stroking speed
([minimum stroking speed + maximum stroking speed/2). If the Stroke Speed Indication is within 2
or 3 SPM of the expected value you do not need to enter Mid Range settings. If the display differs by
more than 2 or 3 SPM from the expected value, enter the Mid Range Output SPM and increase or
decrease the Cal # in the popup Output Cal # entry box until the Stroke Speed SPM is equal to the
Mid Range Output SPM that you entered. Once the correct Cal # is found, enter the Cal # as the
Mid Range Output Cal # setting.
9. Calibration of press drive speed is now complete. Pressing the EXIT CAL MODE softkey will take
you out of the Output SPM calibration mode and automatically set the press stroking speed to the
lowest value on the Motor Speed adjustment screen. It is now possible to set stroking speed by
entering numbers or using the SPM UP and SPM DOWN softkeys on the Motor Speed screen. Now
calibrate Input SPM as described in Section 4.2.2.3.