Weight Checks Module

The Weight Checks Module is a quality control system within Commander4j for capturing, analysing, and reporting on product weight measurements during production. It monitors individual sample weights against statutory and internal tolerances, calculates pass/fail results automatically, and integrates with electronic scales via serial port for automated weight capture.

The module is governed by European average weight legislation, which uses two tolerance thresholds — T1 and T2 — to determine whether a sample is within acceptable limits.

Overview

During production, an operator places products on a connected scale. The system reads the weight automatically (or allows manual entry), collects a configured number of samples, and calculates the sample mean and standard deviation in real time. If individual weights or statistical results fall outside defined tolerances, the system flags T1 (warning) or T2 (critical) failures. All results are stored and are available for historical reporting and trend analysis.

Concepts

Nominal Weight and Tolerances

Each product has a nominal weight — the declared weight stated on the packaging. The Weight Checks Module uses a Tolerable Negative Error (TNE) to define how far below the nominal weight an individual unit may legally fall.

Two thresholds are derived from the TNE:

Threshold	Meaning	Typical value
T1	Warning — weight is approaching the limit	Typically 80% of TNE below nominal
T2	Critical — weight has breached the statutory limit	100% of TNE below nominal

TNE values by nominal weight are defined in the Tolerable Negative Errors table and are used automatically when a sample is taken.

Product Groups

Materials are assigned to Product Groups, which define the nominal weight, tare weight (the weight of the empty container), and tolerance specifications for that group. When an operator selects a process order, the system looks up the material's product group and pre-fills the relevant weight specifications automatically.

Sample Points

A Sample Point represents a physical location in the facility where weight checks are performed — for example, a point at the end of a production line, or in the quality bay. Each sample point is associated with a required resource (production line).

Workstations

A Workstation links a specific computer to a sample point and a scale device. When the Weight Capture screen opens, the system identifies the workstation automatically by matching the computer's name. This determines which sample point and scale to use without requiring the operator to configure anything.

Configuration

Before the module can be used, the following must be set up through the desktop administration screens:

Scales — define each scale device (make, model, serial port settings)
Sample Points — define the measurement locations
Workstations — link each computer to a sample point and a scale
Product Groups — define nominal weights, tare weights, and tolerance specs
Tolerable Negative Errors — define T1 and T2 thresholds for each nominal weight

Supported Scales

The module communicates with electronic scales via a serial port (RS-232/USB serial). The following scale makes are supported:

Make	Reset command	Response format
Mettler Toledo	@	`S S 123.45g`
Avery W-Tronix	C	`1G 123.45g`

Serial port parameters (baud rate, data bits, stop bits, parity, flow control) are configured per scale in the Scale Admin screen.

Sample Size

The default number of individual measurements taken per sample session is controlled by a system key. Individual workstations can override this if a different sample size is required at a specific location.

Screens

Screen	Purpose
Weight Checks Data Capture	Primary screen for operators to record weight samples
Weight Check Reports	Query and report on historical weight sample data
Scale Admin	Create and manage scale device records
Workstation Admin	Create and manage workstation assignments
Sample Point Admin	Create and manage sample point locations
Product Group Admin	Define weight specifications by product group
Tolerable Negative Errors	Define T1/T2 thresholds by nominal weight
Container Codes Admin	Define packaging types

Database Tables

Table	Contents
APP_WEIGHT_SAMPLE_HEADER	One record per sampling session (header information, statistics, pass/fail counts)
APP_WEIGHT_SAMPLE_DETAIL	One record per individual weight measurement
APP_WEIGHT_TNE	Tolerable Negative Error values by nominal weight
APP_WEIGHT_SCALE	Scale device configuration
APP_WEIGHT_WORKSTATION	Workstation-to-scale-and-sample-point assignments
APP_WEIGHT_SAMPLE_POINT	Sample point locations
APP_PRODUCT_GROUP	Product group weight specifications
APP_WEIGHT_CONTAINER_CODE	Packaging type codes