Weight Checks Data Capture
The Weight Checks Data Capture screen is the primary interface used by production operators to record weight samples. It is accessed from the Weight Checks section of the desktop application.
Opening the Screen
When the screen opens, Commander4j automatically identifies the current workstation by matching the computer name against the workstation configuration. This determines which Sample Point and Scale will be used for the session, without requiring the operator to make any selection.
Selecting a Process Order
The operator selects or scans a Process Order to associate the weight checks with the current production run. Once selected, the system automatically retrieves and displays:
- The Material being produced
- The Customer assigned to the order
- The Product Group, which provides the nominal weight, tare weight, and tolerance specifications
- The Container Code (packaging type)
Capturing Weights
Once a process order is selected, the operator begins placing products on the connected scale. Weights can be captured in two ways:
- Automatic (scale integration)
- The scale communicates with Commander4j via the configured serial port. When a product is placed on the scale and the reading stabilises, the weight is captured automatically. The system detects stabilisation by monitoring the transition from a zero reading to a non-zero value, preventing duplicate entries.
- Manual entry
- If the scale is unavailable, the operator can press the Manual Input button and enter the weight via the keyboard.
Each captured weight is added to the current sample. The screen displays a running count of measurements taken.
Real-Time Statistics
As weights are captured, the following statistics are calculated and displayed in real time:
| Statistic | Description |
|---|---|
| Sample Mean | The average of all weights captured so far |
| Standard Deviation | The spread of the measurements around the mean |
| Sample Count | How many individual weights have been recorded |
| T1 Count | Number of individual weights that failed the T1 (warning) threshold |
| T2 Count | Number of individual weights that failed the T2 (critical) threshold |
A live XY scatter chart displays the trend of sample means and standard deviations over time, allowing the operator to see at a glance whether weight consistency is improving or deteriorating during the production run.
Pass/Fail Thresholds
The system evaluates each individual weight against the thresholds defined in the Tolerable Negative Errors table for the product's nominal weight:
- T1 — the weight is approaching but has not yet breached the statutory limit
- T2 — the weight has breached the statutory Tolerable Negative Error limit
When a T1 or T2 failure is detected, the relevant counter increments and the chart updates accordingly.
Completing a Sample
The default sample size (typically five measurements) is set by a system key, and can be overridden per workstation. Once the required number of measurements has been collected, the operator can add optional Comments before saving the record.
On save, the system writes:
- One header record to `APP_WEIGHT_SAMPLE_HEADER` containing the session summary (process order, material, mean, standard deviation, T1/T2 counts, operator, workstation, timestamp)
- One detail record per individual measurement to `APP_WEIGHT_SAMPLE_DETAIL`
Configuration
The behaviour of this screen is controlled by the following:
| Setting | Description |
|---|---|
| Sample Size | Number of measurements per session (default 5; overridable per workstation) |
| Sample Frequency | Recommended interval between samples (minutes); displayed as guidance |
| Graph Max Plots | Maximum number of data points shown on the live chart (default 40) |
| Workstation ID | Auto-populated from the computer name; determines sample point and scale |
See also: Weight Checks Module, Weight Check Reports, Tolerable Negative Errors