Priva Compass Installation Manual page 111

10. The display will now show the text Max #kg/5V . This is the maximum number of kg nett weight
that the analog outputs can pass to the process computer. This maximum nett weight must be
derived from the saturated slab weight. Keep a safety margin for plant weight increase due to
plants which are not fully supported. The weighing indicator will show a 5000 mV output voltage
at this maximum number of kg.
This maximum number of kg should never be exceeded by the nett weight. Therefore it is not
advisable to adjust this figure.
11. Press "Enter".
12. Set the desired number of kg by means of the arrow keys and press "Enter" to confirm.
13. Press "Esc" to leave the menu and reactivate the menu protection.
Testing outputs signals and cabling (to be performed by service engineer only at first
commissioning)
The weighing indicator has been fitted with a function which gives you the opportunity to check the
cabling from the analog outputs to the process computer, so it can be established whether these
are functioning properly. In reverse phase, both analog outputs will transmit a block wave during
5000 seconds: a high and a low signal of respectively 0 mV and 0 mV. The 5000 mV of the first analog
output equals 30 kg value, the 0 mV will match the Max #kg/5V set value.
If the measuring data are not given correctly by the process computer, this signal can be used to
check whether a signal is transmitted through the cable. The signal can also be used to weaken the
signal for connection to the process computer.
1. Go to the Test Outputs menu.
2. Deactivate the menu protection by pressing "Enter" followed by " ↑ " and hold this key combination
down for 3 seconds. <<MENU>> will change to >>MENU<<.
3. Press "Enter" to activate the menu.
4. The display will now show Toggle Outputs; press "Enter".
5. Press "↑" and "Enter" to set the setting to 1. Now a 30 second signal will be controlled to the
process computer, first 0 mV followed by 5000 mV. During this signal, the analog outputs are
controlled in reverse phase, i.e. output 1 will be 0 mV and output 2 will be 5000 mV followed by
a 30 second signal in reversed order.
6. Perform the desired calibration or check with the 0 mV and 5000 mV signals. Wait 30 seconds
for the next signal to be given. LED T2 will now give four flashing signals.
7. Go to the weighing indicator and change the setting Toggle Outputs from 1 to 0 by pressing "Enter"
and " ↑ ", followed by "Enter" again.
8. Press "Esc" to leave the menu and reactivate the menu protection.
Recording essential data
The calibration data will be lost if there is a defect in your weighing indicator. The Service menu can
be used to re-enter the old calibration values, immediately after the weighing indicator has returned
after being repaired. Using the known Service menu can data for the weighing platforms and the
number of platforms, the Groscale can be started up again without re-calibrating a dry and a saturated
slab . (for this is not possible during growing since the weighing platforms are already loaded with
substrate slabs)
It is highly recommended to copy the calibration data on the form found in the weighing indicator.n
When you have calibrated the slab, you should go to the Measurements menu using the arrow keys.
From this menu you need to get the values Tare Weight, Saturated Slab and Max #kg/5V and enter
them on the form which accompanies the weighing indicator. These values should be recorded after
every calibration (which is usually once every growing season).
The form should be returned to its little bracket behind the weighing indicator.
Placing plants on the slab
You can now place the plants on the substrate slabs. When weighing the water in the slab you should
prevent the weight of the plants themselves from being weighed as well. The way you do this depends
on the type of crop. Plants which are suspended from wire can be supported. For other crops,
another solution will have to be found or you will have to accept the weight of the plant as being
part of the weighing result.
Installing Priva Compass - 00.014
Groscale
109