Speed Span - MERRICK Genetix Safety, Installation, Operation And Maintenance Manual

Speed Span

(Main Menu > Calibration > Speed Span)
The Speed Span procedure is the process by which the controller relates the length
of the belt (which you must enter) to the number of tacho pulses representing one belt
revolution. It is very important for the accuracy of the speed calculation, for
totalization and for the repeatability of Calibration procedures.
Note: Before you perform a Speed Span procedure, you must measure the belt
accurately and enter the Belt Length into the Genetix controller (see Calibration >
Numeric Data > Belt Length). Also the Speed Span procedure must be performed
before all other calibration procedures.
The objective of this test is to allow the controller to count the number of pulses
representing one belt revolution. To do this, either a switch on the Feeder Connection
Board is used, or this User Interface. For this test, you should place a mark on the
belt and select a suitable reference point to establish when the mark passes by. The
belt must be running.
When you select the Speed Span procedure from the above menu, you will be
presented a screen that shows the number of pulses from Tacho 1 (and Tacho 2, if
configured). At the top of the screen you will also see a note showing you how many
revolutions of the belt the controller is expecting you to run. Generally, more than one
revolution of the belt is used, for accuracy (see Main Menu > Calibration > Numeric
Data > Test Revs to set this parameter). The controller will divide total number of
pulses counted by the number of revolutions to arrive at the number of pulses per rev
("Pulses/Belt Rev", see Main Menu > Calibration > Numeric Data > Pulses/Belt Rev
x).
If your feeder is equipped with a Merrick Feeder Connection Board, with a switch,
then you should turn the switch OFF. When you do this, the pulse counters on the
display should stop incrementing. Press the Enter key to start counting pulses, and
the display(s) should reset to zero.
When your mark on the belt passes your reference point, you should turn the switch
to the ON position. Try to be as accurate as possible. While ON, the controller display
should be incrementing pulses.
Allow the required number of belt revolutions to take place (see above), and when the
mark again passes the reference point, again turn the switch OFF. Pulses should now
stop.
At this point, press the Enter key to allow the controller to make the calculation of
Pulses/Belt Rev. A new screen will be presented that shows the Current value and
the New value. Press the Enter key again to accept the new value or the Menu/Esc
key to exit without making any changes.
If your feeder is not equipped with a feeder connection board, or a switch, then use
the following procedure to perform a Speed Span:
With the belt running, and the controller incrementing pulses, press the Enter key
when your mark on the belt passes the reference point.
Allow the required number of belt revolutions to take place (see above), and when the
mark again passes the reference point, press the Enter key to stop counting pulses
and calculate Pulses/Belt Rev. A new screen will be presented that shows the
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