Kistler-Morse KM Weigh II - Manual (Page 30)

5-2
Chapter 5. Inputs and Outputs
material weight of 2,500 lbs (2,000 lbs plus
the 500 lb deadband).
Figure 5-2. Setpoint Example
If the Weigh II detects a problem, one of three
fail-safe (Fsafe) conditions can be applied to
a setpoint:
1. On
2. Off — default
3. NC (no change)
The On setting energizes the setpoint in a
fail-safe condition. The Off setting de-
energizes the setpoint in a fail-safe condition.
The NC setting means no change is made to
the setpoint condition in a fail-safe condition
(i.e., whatever was energized before the
problem was detected will continue to be
energized). A fail-safe condition remains in
effect until the problem has been corrected.
The following are examples of conditions of
fail-safe conditions:
• ADC (analog-to-digital converter)
overrange/underrange condition
• Engineering units overrange
Report
When this menu is accessed, the display
shows all setpoints assigned to the current
vessel. A typical display looks like this:
• SP2 is the setpoint label
• Slot 02 is the slot number of the setpoint
PCB
• Chan# 03 is the relay channel of the
setpoint on the setpoint PCB
Pressing any key other than the Esc Key or
Auto/Man Key cycles through the reports for
all other assigned setpoints for this vessel.
SP1=9,000
SP2=2,000
8,000
2,500
Deadband = 1,000
Deadband = 500
Hi
Lo
vessel or math channel. These are labeled
SP1 for setpoint 1 through SP8 for setpoint 8.
Note
Depending on the options you
selected, up to a total of 16 setpoints
can be assigned in the Weigh II, with a
maximum of 8 setpoints for one vessel
or math channel.
Once you have selected a setpoint to set up,
the activation value (Val), the point where the
setpoint relay changes state, can be entered.
This value is entered directly with the Alpha-
numeric Keys or scrolled to with the Up and
Down Arrow Keys. The “-” Key is used to
toggle between the positive and negative
value of the number entered. Setpoint relays
can be configured to change state either
above (Hi) or below (Lo) the setpoint value.
The deadband (Dead) value determines the
point at which a setpoint relay returns to its
normal on/off state after the relay has been
activated. The deadband value equals the
amount of material that will be added or
removed from the vessel before the setpoint
relay is deactivated. Kistler-Morse recom-
mends the use of a non-zero deadband to
prevent relays from oscillating. The value is
entered directly or scrolled to with the arrow
keys. The default value is 10. Pressing the
Enter Key saves the new value.
The setpoint relays can be set to activate
from the net weight or the gross weight
(Net/Grs) of the material in the vessel.
Activating based on the gross weight is the
default mode of the Weigh II.
Example: See Figure 5-2. A vessel with a
9,300 lb capacity has setpoint 1 (SP1) set at
9,000 lbs gross weight. The Hi/Lo function is
set to Hi and the deadband (Dead) is set at
1,000 lbs. When the contents exceed 9,000
lbs, the setpoint energizes, activating a pump
to remove material from the vessel. The pump
continues to operate until the setpoint de-
energizes at a material weight of 8,000 lbs
(9,000 lbs minus the 1,000 lb deadband).
This vessel also has a setpoint 2 (SP2) set at
2,000 lbs gross weight. The Hi/Lo function is
set to Lo and the deadband (Dead) is set at
500 lbs. When the contents falls below 2,000
lbs, the setpoint energizes, activating a pump
to fill the vessel. The pump continues to
operate until the setpoint de-energizes at a
SP2 Output Chan
Slot 02 Chan# 03
F1 F2 F3