Sales
Sell, Verify and Recover a Weighed-Item Sale
In the desktop app, adding a weighed item can trigger a scale read. Posnic prefers a stable positive reading and updates the cart quantity to three decimals. If hardware is unavailable, the item can remain at quantity 1, so the cashier must correct and verify it before payment.
- Menu path
- Add -> New Sale
- Verified from
- Posnic demo and current POS source reviewed on 2026-09-08
Technical source evidence
frontend/static/script/js/modules/js/sales.js weighed-item detection read trigger manual fallback and three-decimal update, frontend/static/script/js/modules/js/weight-bridge.js six-second settled read and browser fallback, frontend/modules/sales_write.html weight control, api/src/models/sale.model.js fractional quantity minimum 0.001, Live browser limitation audited 2026-09-05
Normal Sale
- Open New Sale in the Posnic desktop app and confirm the correct branch and open register.
- Make sure the scale shows zero with an empty platform.
- Place only the product being sold on the scale and wait until its reading is stable.
- Scan the product barcode or search and add the exact weighed item.
- Wait for Posnic to read the scale. The bridge waits up to six seconds for a settled frame.
- Confirm the cart quantity shows the measured weight to three decimal places.
- Independently check quantity x unit price, then review discount, tax and final total.
- Only continue to tender after the customer and cashier can see the correct quantity and amount.
Use the Weight Control
The scale control reads the current weight. If another text field is focused, Posnic may place the three-decimal reading into that field; otherwise it updates the newest or first cart row. Select and verify the intended line before using it.
- Place and settle the item.
- Make sure no unrelated text input has focus.
- Use the weight control.
- Confirm the intended cart row changed and no other field was overwritten.
- Recheck the line and sale total.
No Reading or Disconnection
Do not tender a weighed item left at quantity 1 unless one full configured unit is genuinely being sold. When the feature is off or the scale is disconnected, Posnic warns but does not block the sale.
- Stop before payment and read the warning.
- Check scale power, cable, port and Hardware Manager connection.
- Remove all load, confirm zero, replace the item and retry the read.
- If the shop authorizes manual fallback, enter the independently measured quantity to three decimals.
- Have the cashier or manager compare the quantity and calculated amount before tender.
- Record repeated failures and move the till out of weighed-item service until repaired.
Browser Limitation
- A browser can manage records and settings, but its weight bridge reports that the desktop app is required.
- Do not interpret a visible Weight control in a browser as a connected device.
- Use the installed desktop till for acceptance and live weighed sales.
Troubleshooting
| Symptom | Risk | Action |
|---|---|---|
| Item enters at 1.000 | Overcharge or undercharge | Do not tender; reconnect or enter an independently verified manual weight. |
| Reading is zero | Empty or unreadable platform | Check placement, zero state and Hardware Manager data. |
| Reading jumps | Unstable load | Wait for stability and keep hands, bags and other products off the platform. |
| Wrong cart line changes | Another line was newest/first or an input had focus | Correct the line, clear focus and repeat deliberately. |
| Browser warning appears | No serial bridge | Move the transaction to the desktop app. |
| Total is unexpected | Wrong price unit, tax, discount or quantity | Suspend payment and review the item master plus line calculation. |
Shift Control
- Run a known-weight opening test and record the expected and observed line amount.
- Keep the platform clear between products and confirm zero regularly.
- Repeat the test after reconnect, desktop restart or port change.
- Reconcile suspicious voids, manual quantities and weighed-item totals at shift close.