WeighTech MicroWeigh User manual

MicroWeigh Standard Bagger/Bulker
WeighTech, Inc. Staff
Waldron, Arkansas
1-800-457-3720
November 12, 2012

Contents
1 Introduction 4
1.1 MicroWeighFeatures.......................... 4
1.2 MicroWeigh Applications . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Keypad Operation 4
3 Main menu items 5
3.1 “Poweroff”............................... 5
3.2 “Washdown” .............................. 5
3.3 “Totals” ................................. 5
3.4 “Calibrate” ............................... 5
3.5 “SetupMenu”.............................. 5
3.6 “Auditcfg” ............................... 5
3.7 “Auditcal” ............................... 5
3.8 “Tare”.................................. 6
4 How to Step Through Menus 6
4.1 Menus can contain several different items . . . . . . . . . . . . . . . 6
4.2 Howtoenteranumber ......................... 6
4.3 How to select from a list . . . . . . . . . . . . . . . . . . . . . . . . . 7
5 General Scale Operations 7
5.1 ScaleOnProcedure............................ 7
5.2 ScaleOffProcedure............................ 7
5.3 ZeroProcedure ............................. 8
5.4 UnitsProcedure............................. 8
5.5 TareOperation ............................. 8
6 Machine Setup 8
7 Machine Operation 10
7.1 Startup.................................. 10
7.2 Shutdown ................................ 10
7.3 Cleanout................................. 10
7.4 TargetWeight.............................. 10
7.5 Tolerancing ............................... 10
7.6 DumpCycle................................ 11
8 Calibration Procedure 11
8.1 Entering the calibration menu . . . . . . . . . . . . . . . . . . . . . . . 11
8.2 Keyingincalweight .......................... 12
8.3 CalibrationExample .......................... 12
8.4 Establishingazero ........................... 12
8.5 Accepting a cal weight . . . . . . . . . . . . . . . . . . . . . . . . . 12
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9 Scale Parameters 12
9.1 “Units” ................................. 12
9.2 “Capacity”................................ 13
9.3 “Resltn”................................. 13
9.4 “Stability”................................ 13
9.5 “Motionsns” .............................. 13
9.6 “Prefilter”................................ 13
9.7 “AZT”.................................. 13
9.8 “AZTband”............................... 13
9.9 “Calibrate” ............................... 13
9.10“IZset” ................................. 14
9.11“lbunits” ................................ 14
9.12“kgunits” ................................ 14
9.13“gunits”................................. 14
9.14“ozunits” ................................ 14
9.15“Defaults”................................ 14
10 Display Messages 14
10.1 General Warning/Error Messages . . . . . . . . . . . . . . . . . . . . 14
10.2 Calibration Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . 15
11 Menus 16
11.1MainLevel ............................... 16
11.2Production................................ 16
11.3Totals .................................. 16
11.4Setupmenu ................................ 17
11.5Parameters................................. 17
11.6Dumpsettings.............................. 18
11.7I/Otest ................................. 18
11.8Infomenu................................ 19
12 Troubleshooting 19
12.1Loadcells................................ 19
12.2Machines ................................ 20
12.3 Before calling WeighTech... . . . . . . . . . . . . . . . . . . . . . . 20
12.4ModuleAssignments .......................... 20
13 Replacement Parts 21
14 Wiring Diagram 22
15 Load Cell Color Codes 23
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1 Introduction
With the WeighTech MicroWeigh a combination of state-of-the-art technology with
common down-to-earth basics creates a digital indicator that makes troubleshooting and
actual maintenance repair so simple that anyone can be trained to make repairs on this
indicator in just minutes.
1.1 MicroWeigh Features
•High impact ABS alloy construction.
•Highly visible, easy-to-read display with adjustable contrast and backlight.
•Environmentally sealed touch-sensitive operator control panel.
•Standard units of measure include grams, kilograms, ounces, and pounds.
• RS-232 and Infrared communications are standard with RS-485 option available.
•Wireless data collection using a PDA with WeighTech data-sync software.
1.2 MicroWeigh Applications
•Standard weighing
•Label printing
•Tank or vat weighing
•Checkweighing (boxes, bags, and pieces)
•Bench and floor scales
•Batch weighing
2 Keypad Operation
The WeighTech MicroWeigh keypad is a watertight sealed touch sensitive sensor. The
keys are actually sensitive to contact area, not force. Press lightly with the ball of your
fingertip as though you were giving fingerprints. Best results come from using the
ball of your finger, not the very tip. Most objects will not trigger the keypad–knives,
screwdrivers, tools, etc. do not have enough surface area in contact with the key to
register as a keypress. (You might get it to trigger with a medium sized conductive bolt
head, if you have skin in contact with the bolt.)
One consequence of the design of the touch sensitive keypad is that it is sensitive
to water streams. For this reason, WeighTech includes a unique “washdown mode” to
prevent unwanted keypad activity during washdown/sanitation/cleanup intervals. When
the indicator is in washdown mode, the indicator will weigh normally but the keypad is
locked out.
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To unlock the keypad, you must play follow the leader. One key will be lit. Press
it. Another key will then light up. Press it. Continue until the indicator displays “Exit
washdown”. The indicator will require that you press five keys in a row correctly before
it will unlock the keypad. Any wrong keypress will restart the counter back to five. The
odds are extremely slight that random water splashing would ever be able to trigger the
correct keys in the correct order to unlock the keypad.
3 Main menu items
3.1 “Power off”
Touch the enter key to select this menu item, which will power down the indicator. If
the auto-on jumper is installed on the interface board, the indicator will immediately
turn back on.
3.2 “Washdown”
This function puts the indicator in washdown mode to prevent inadvertent keypad
activity. See the washdown section of this manual for more information.
3.3 “Totals”
This function leads to the totals submenu.
3.4 “Calibrate”
This function allows you to calibrate the scale. Refer to the calibration section of this
manual for details.
3.5 “Setup Menu”
Enter the setup submenu, where scale parameters can be viewed or set.
3.6 “Audit cfg”
Displays the audit counter for configuration. Every time a sealed scale parameter is
modified this counter will increment by one. This setting is nonvolatile (it will be
retained even if the batteries go dead) and cannot be altered except by modifying an
audited configuration parameter.
3.7 “Audit cal”
Displays the audit counter for calibration. Every time the scale is calibrated this counter
will increment by one. This setting is nonvolatile (it will be retained even if the batteries
go dead) and cannot be altered except by performing a calibration.
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3.8 “Tare”
Keypad entered tare: Touch the Enter key to set a new pushbutton tare by scrolling
through digits one place at a time. Keypad tare values are entered in the current units,
and are limited to be greater than gross zero weight and less than the indicator capacity.
Entering a tare of zero will clear any existing tare from indicator.
4 How to Step Through Menus
From the main weight display, press the “Menu/Help” key. You are now in a menu, and
the keys now have different functions:
Cancel Help Enter Down Up
•“Cancel” will back you out of the menu one level at a time.
•“Help” will display information about the current choice (option).
•“Enter” has various functions, depending on where you are in the menu.
•The “Down” key will scroll backward through the menu choices.
•The “Up” key will scroll forward through the menu choices.
4.1 Menus can contain several different items
An item with a “*” on the right end will do something when you press the enter key–
something might be turn the indicator off, drill down into another menu, clear totals, or
start a calibration routine. The item with a numeric value (scale capacity, for instance)
at the right side of the display might allow you to change the number by pressing the
enter key. An item with text (such as “on” or “off”) at the right side of the display might
allow you to select from a list of options by pressing the enter key. Some items are just
for reference and cannot be changed at all. Examples of reference items would be the
software name and revision–these are set when the software is written and cannot be
changed.
4.2 How to enter a number
Using the calibration routine as an example: Press the “Enter” key. The indicator display
will show “Cal weight ” and the cursor will be blinking. The blinking cursor is the
clue that you can enter an arbitrary number using the up, down, right, and enter keys.
Pressing the up/down keys will scroll through the list (0 1 2 3 4 5 6 7 8 9 - . ) in
turn. When the desired number appears, press the right arrow (menu/help) key. The
blinking cursor will advance one digit to the right, leaving your selected number in
place. Continue this sequence until the desired numeric value is visible on the display.
Press the “Enter” key to accept the value, or the “Cancel” key to abort.
Example: Enter a calibration weight of 25 pounds
•Start with the indicator at a normal weight display (“ 0.00 lb”)
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•Press the “Menu/Help” key
• Scroll through the main menu using the up or down arrow keys until “Calibrate *”
is displayed on the indicator
•Press the “Enter” key to start the calibration routine
• The indicator may display “Password” if a calibration password is required. If so,
enter it (default calibration password is “Zero” “Zero” “Zero”)
•The indicator should now be displaying “Cal Weight” and a blinking cursor.
•Press the up arrow key. The display should now show “Cal weight 1”
•Press the up arrow key again. The display should now show “Cal Weight 2”
• Press the right arrow key to accept the first digit (2) and advance the blinking
cursor to the next digit. The indicator should display “Cal weight 2 ”
• Press the up arrow key five times to select a 5 as the second digit. The indicator
should now display “Cal weight 25”
•Press the “Enter” key to accept 25 pounds as a calibration weight.
• The indicator will display “Cal–zero weight”. Press the “Cancel” key to abort the
calibration process.
4.3 How to select from a list
This is very much like stepping through a menu. Some settings (such as displayed
resolution) must be limited to one of several predetermined values. To edit one of these
settings, press the “Enter” key. The currently selected value will move from the far right
of the display to the left. This indicates that you may use the up and down arrow keys to
scroll through a list of possible values for this setting. Once you’ve selected a value for
the setting, press the “Enter” key to complete the selection process. As always, pressing
the “Cancel” key will cancel the selection and restore the setting to the previous value.
5 General Scale Operations
5.1 Scale On Procedure
Touch the “Zero / On” key. Indicator will come on and display will read “MicroWeigh
by WeighTech” and then continue to the weigh mode. At this point the scale is ready
for product or operator input.
5.2 Scale Off Procedure
To turn the scale off touch the “Menu / Help” key. The indicator will display “Power off
*”. At this point touch the “Print / Enter” key and scale display will go blank, and the
indicator will be off.
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5.3 Zero Procedure
To zero the indicator touch the “Zero / On” key and the indicator will take a new zero.
If the current weight reading is unstable, under capacity, or over capacity, no new
pushbutton zero will be established.
5.4 Units Procedure
To change the units of measure touch the “Units / Cancel” key. The units will change
between pounds, kilograms, grams and ounces (assuming all the units are enabled in the
“Parameter” menu) each time that the key is touched.
5.5 Tare Operation
Press and hold the tare button to establish a pushbutton tare reference. If a valid tare is
established, the indicator will switch to the net weight display. If the gross weight is
equal to or less than gross zero, any existing tare value will be cleared, the display will
show “Tare cleared” for about one second, and the display will revert to gross weight
display.
Toggle between net and gross display modes by touching the “Tare” button. If no
tare reference has been established, the indicator will not switch to net weight mode.
An arbitrary tare weight can be entered from the tare setting in the main menu
(keypad tare). Scroll and select digits one at a time to enter the desired value. The
indicator will not accept a keypad tare value in excess of scale capacity, or less than
zero. Entering a value of zero will clear any existing tare and return the indicator to the
gross weight display mode. Units for the entered weight is the same as the currently
displayed units. (To enter a six pound tare, be sure that the display is showing weight in
pounds before entering the keypad tare.)
6 Machine Setup
• After the machine has been wired and plumbed, turn on the air supply and turn
off the Microweigh control indicator. The buffer hopper (top hopper) and weigh
hopper (bottom hopper) should both be open, the infeed belt (if controlled by
the system) should be running, and all knockoff gates should be retracted. Any
cylinder in the wrong position is probably plumbed incorrectly. Press the small
silver pilot on each pneumatic solenoid valve in turn to check that the cylinders
move freely and that there are no air leaks.
• Turn on the indicator. No gates should move. Put the indicator in the cycle off
mode (“Production”/“Cycle Off”). The buffer hopper and weigh hopper gates
should both shut, and the infeed belt should turn off (if controlled by the system).
If not, check the wiring, modules, and jumper configuration.
• Next, put the indicator in cycle on mode (“Production”/“Cycle On”). The weigh
hopper gate should close, the buffer hopper gate should open, and the infeed belt
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should run (the system is trying to fill the weigh hopper). If the weigh and buffer
hopper gates are swapped check the wiring—the weigh hopper valve is probably
wired to the buffer hopper output module.
• After powering up the indicator, you may see “Setup Required” on the display.
If so, go into the “Parameters” menu and set the scale capacity. “Cal required”
means that the indicator has not been calibrated, and calibration must be done
before the machine will operate. Once the capacity has been set and the indicator
has been calibrated, you may want to adjust some of the values in the “Dump
setting” menu.
• “Target” should be set to the desired target weight of the dump. “Dump Limit” is
the hopper capacity, or maximum size of a single dump. In most cases this will be
set at the factory and won’t require adjustment. If the target weight is set above
the hopper capacity the system will go into batch mode and make multiple dumps
at hopper capacity to reach target weight. That’s probably not a good plan for a
bagging system, so ensure target weight is less than dump limit when filling bags.
• If the infeed is controlled by the system tune the “Line stop” timer. The line stop
timer controls how long the infeed is allowed to run after the weigh hopper has
reached target weight. Adjust this timer long enough that the buffer hopper is
prefilled for the next dump, but not so long that the buffer hopper overflows when
all the output bins are full.
• Baggers should have the “Bag” setting turned on to enable the bag opener. Obvi-
ously, turn the setting off on a bulker.
• Determine if a dump switch is required and how it should work. Most baggers use
“Dump sw” set to “first”, which will hold the first (and only) dump in the weigh
hopper until the operator presses the dump switch. Batch mode bulkers have more
options. If you’d like to hold off only the first dump (to allow the operator to
place the box under the weigh hopper), set “Dump sw” to “first”. Another option
would be “last”, which will hold off the last dump of the batch so that the operator
can manually adjust the final dump to make weight. The “f+l” setting holds off
both the first and last dumps in the batch. The “all” option will require the dump
switch to be pressed before each dump, and the “none” option will never require
the dump switch to be pressed before dumping.
• The standard dump switch is a momentary normally open contact. If a normally
closed contact must be used instead, set the “Switch type” setting to “rev”.
Otherwise, set to “std”. (There’s also an “off” option to completely disable the
dump switch.)
• There is provision for an optional idle/washdown button. Wire a maintained
contact switch to module M6. When the switch contacts close, the indicator will
go to the cycle idle mode. When the switch contacts open, the machine will start
the operating cycle (cycle on). If the switch operates backwards, flip the “Dump
settings”/“Switch” setting.
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7 Machine Operation
7.1 Startup
Ensure that all hoppers are empty and that all moving parts are in good working
condition. Power up the machine and indicator. No air cylinders should move when the
indicator is powered on.
Touch the “Menu” key, scroll until “Production” is visible, and touch the “Enter”
key. You can now scroll between the production options, so scroll until “Cycle On” is
visible, and touch “Enter”. The display will show “Dump Cycle On”, pause for a second
or so, and return to the normal weight display. The machine will now begin operation
(buffer hopper gate will open and the weigh hopper gate will close). You may also
notice that the left side of the display now shows “On”. This indicates that the machine
is in the automatic weighing cycle. (If the machine is equipped with a washdown or idle
button, you can pull the switch out to start the automatic operating cycle.)
7.2 Shutdown
From the normal weight display, touch the “Menu” key. Scroll up or down until you
reach the “Production” menu. Touch the “Enter” key, and again scroll until “Cycle Off”
is visible on the display. Touch the “Enter” key. The display will show “Dump Cycle
Off” for a few seconds, return to the normal weight display, and go into the off mode.
In off mode, all hopper gates will close to prevent product flowthrough and the machine
will not cycle. The left side of the display should show “Off” in this mode.
7.3 Cleanout
Select “Cycle Idle” from the “Production” menu to enter idle mode. In idle mode, the
hopper gates will all lock in the open position to allow cleaning. The indicator display
will show “Idle” on the left side when the machine is in this mode. (If the machine
is equipped with a washdown or idle button, you can push the switch in to place the
machine in idle mode.)
7.4 Target Weight
The target weight can be changed while the machine is in any operating mode, even
while running production. Touch the “Menu” key, scroll until “Production” is shown on
the display, touch “Enter”, and scroll until “Target” is visible. Once the target weight is
visible on the display, touch the “Enter” key to modify it. Use the up or down arrows to
adjust each digit in turn and press either “Enter” to set the new target weight, or “Cancel”
to leave the target weight setting unchanged.
7.5 Tolerancing
If the tolerance option is enabled, the hopper will not dump unless the hopper weight is
in the acceptable weight range. The acceptable weight range is set by the low and high
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