36
Off
>
5.20
2
Off
<=
5.20
3
// Now the “over” (yellow) light to be on
anytime the weight is above 5.2lb
On
>
5.20
3
When this formula is executed, the scale evaluates each line in order. This calculation is done in memory only, and the outputs are not
affected until the formula is complete. The entire formula is evaluated on each and every display update, which is programmable
through the system menu.
You may wonder why it is necessary to have to use an On condition at the beginning. This was done to increase flexibility as there may
be many cases where the user wants the light to start in the on state, turn off during a certain weight range and on again when above
that range. You have to specify every possible condition for the output when making formulas.
This last example will show an automated filling operation using the cycle option. The goal here would be to have output #1 connected
to a filling valve and the cycle starting with this valve in the off condition. The user places a box on the scale below the filling
apparatus, press the ZERO key to zero out the weight of the box, press the ENTER key to start filling and have the setpoint controller
switch the filling valve off when 5lb is reached. The user then removes the box from the scale and the output will remain off until the
next cycle is initiated by pressing the ENTER key.
Start in the setpoint definition screen by enabling the CYCLE option and setting the INIT option to off.
Here is the formula:
CMD EXP
VALUE
OUT
On
<
5.00
1
// Will actually go on as soon as the ENTER key is pressed.
Off
>=
5.00
1
// Switch off at 5 lb and end cycle
That’s all there is to it. The output will go
off at 5lb and remain off until the next cycle.
Notes on Cycle Mode
The cycle function is used when it is desirable to “latch” the output to a specific state when a process is complete. Conside
r the
following examples with and without the cycle option. In both cases the setpoint is set to fill a box to 5lb and then shut off.
Cycle Off
: The output is on as the box fills and the scale monitors the process. At 5lb the output switches off. The user then removes
the box from the scale. When he does that, the indicated weight falls below 5 lb, the filling valve switches back on dumping material all
over the platform.
Cycle On
: When 5lb is reached the output switches off, and remains off until the user initiates the cycle again by pressing the ENTER
key.
There are two other points concerning process cycles:
1.
There may only be one cycling setpoint definition active at any given time. All other activated setpoint definitions will work
normally along with it.
2.
To abort the cycle, press the ENTER key. The output will then obtain the same state it would have taken if the process had
completed normally.
When changing the command line operations within a Cycling Setpoint Definition, you must
REBOOT
the scale for the settings to take
effect. This requirement is only for a Cycle mode setpoint. If you do not reboot, then the previous settings will continue to remain
active.
