Epson 9840 - Manual (Page 17)

I N T E R F AC E M O D E L 9 8 4 0 V E R 6 . 0 . 2
1. Source: -- This entry allows you to scroll through a list (using the left/right or
plus/minus buttons) to select the source of the data that will drive the analog output.
The standard list will include load or torque, peak, valley, gross, position, and velocity.
Channel A+B is an option which, if chosen, will appear only if the cells on both
channels are of the same type. Press enter to select the displayed item.
2. Units: -- This entry allows you to scroll through the list of available units for the data
source you have chosen in the previous step.
3. Full -- This entry specifies the value of source data (in the selected units) that will
cause the Model 9840 to output positive full scale analog voltage (+10.0 volts).
4. Zero -- This entry specifies the value of source data (in the selected units) that will
cause the Model 9840 to output zero analog voltage (0.0 volts).
Once you have entered these 4 selections the analog output is setup.
4-20MA Output Option
This option allows the user to output with current (milliamps) rather than voltage. It
operates similarly to Analog Output using the same submenus, but, in this case, the Full
and Zero data entered control the distribution of output in milliamps from the unit given
certain inputs to the cell. Particularly, the number entered for Zero will set the
corresponding input in Lbs to output 12 milliamps (the mid-point between four and twenty
milliamps) and the unit will extrapolate other output values between 4 and 20 milliamps.
If this option is enabled, the following steps will set up the unit: follow the instructions for
Analog Output until "Source:" is displayed. Toggle through until the "Load A" is on the
display. Press the enter button to bring up the "Lb" menu. Press the enter button again
and the "4.0000 Lb Full" menu will be displayed. This is where the maximum Lbs for the
cell should be entered. Press enter and the "0.0000 Lb Zero" menu will be displayed.
This is where the offset from zero (the value in lbs that will give a 12 milliamp) should be
entered. Press the enter button to return to the Analog Output menu and then press the
escape button to return to the normal display.
Example outputs with varying Full and Zero Values (assuming a 4.00 Lb calibrated cell
with 10 V excitation):
1. Full = 4.0000 Lb
Zero = 0.0000 Lb
(Input) Mv/V (Output) Volt (Output) MA
4 10v 20mA
3 7.5v 18mA
2 5.0v 16mA
1 2.5v 14mA
0 0v 12mA
-1 -2.5v 10mA
-2 -5.0v 8mA
-3 -7.5v 6mA
-4 -10.0v 4mA
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