Scale guide

Connecting a scale to FloorCheck, and what to do when it doesn't connect.

Not every scale will work. Run Set up a scale with yours before relying on it: it tells you on the spot whether FloorCheck can read it, and checks it against a known weight. Nothing here needs an internet connection.

What you need

A scale with a data output. Most bench and precision scales have an RS-232 port (a 9-pin connector, sometimes an RJ or round connector) or an optional interface. Look for "RS-232", "COM", "Interface" or "Print" in its menu or manual.
A Bluetooth Low Energy link to it. Either a scale with its own BLE module, such as Kern scales with the KUP-06 adapter, or a BLE serial adapter that plugs into the RS-232 port. Choose a Bluetooth Low Energy (BLE, Bluetooth 4.0 or newer) adapter: older "Bluetooth 2.0 SPP" adapters work with some Android devices but never with iPhones or iPads.
A check weight of known mass, such as a 500 g test weight, to confirm the reading.

FloorCheck recognises adapters that use Kern's KUP-06 service, the Nordic UART service, HM-10-style modules and Microchip transparent UART. For any other BLE adapter it looks through the device's services for one that behaves like a serial port.

Formats FloorCheck reads

Every scale brand sends weights in its own text format. FloorCheck listens to what your scale sends and works out which one it is.

Format	Used by	How FloorCheck gets a weight
MT-SICS	Mettler Toledo balances and scales; Kern (KCP follows it for weights)	Asks the scale to stream every change
A&D standard format	A&D balances and scales	Asks for each weight
Ohaus print format	Ohaus Scout, Ranger, Valor, Defender and others	Asks for continuous output, or for each weight
Sartorius SBI	Sartorius balances	Asks for each weight
SMA	Scales and indicators that follow the Scale Manufacturers Association standard	Asks for each weight
Toledo continuous	Industrial bench and floor scale indicators, including many from Mettler Toledo, Rice Lake and Cardinal	Listens: the indicator streams on its own
Plain weight output	Any scale that prints a number and unit, one reading per line	Listens, and waits for the reading to hold still

If your scale sends something else, FloorCheck tries to learn it from the scale's own output: where the weight is, its unit, and the mark that means a reading is still settling. You confirm it with a check weight before it's saved.

Wiring an RS-232 scale

Serial settings must match. Find the scale's baud rate, data bits, parity and stop bits in its menu (9600 baud, 8 data bits, no parity, 1 stop bit is the most common) and set the adapter to the same. A mismatch shows up in FloorCheck as scrambled data.
Straight or null-modem. On a 9-pin connector, data travels on pins 2 and 3 with ground on pin 5. If nothing arrives, the scale and adapter may both be sending on the same pin: add a null-modem adapter (it swaps pins 2 and 3), or try the other cable type.
Turn the output on. Many scales ship with the port off, or set to print only when a key is pressed. Set it to send on request, continuously, or on stable readings.
Power. Some adapters take power from the port and some need their own supply; check the adapter's manual.

Setting it up

Turn on the scale and the adapter, and keep the phone or tablet within a few meters.
In FloorCheck: Settings, Scale and instruments, Set up a scale, then Find my scale. Known adapters are listed first.
FloorCheck listens to the scale. If it's quiet, it asks for a weight in each brand's own words, and tells you which format it found.
Zero the scale with the pan empty, put the check weight on, enter its mass and tap Check.
Name the scale (for example "Line 3 scale") and save it. It reconnects on its own after that.

No scale yet? The setup has a demo scale that speaks each format, so you can see the whole process first.

Troubleshooting

What the setup says	What to try
Isn't sending anything	Turn on the scale's data output in its menu. Check the cable: try a null-modem adapter. Make sure the adapter has power.
Data is scrambled	The adapter's speed or parity doesn't match the scale. Set both to the same settings, usually 9600 baud, 8 data bits, no parity, 1 stop bit.
No weight found	Put something on the pan so the reading changes. Check the scale is set to send weights, not a report or a count.
Kilograms or pounds with no unit	The scale is sending a bare number in another unit. Set the scale to grams.
Reads zero	Put the check weight on the pan, and zero the scale with the pan empty first.
Off by a few grams	Zero the scale with the pan empty and check its calibration with your check weight.
The device doesn't appear	Allow Bluetooth for FloorCheck, move closer, and make sure the adapter isn't connected to another phone or computer.

Accuracy and legal-for-trade

For net-contents checks, NIST Handbook 133 expects a scale whose division is no larger than one sixth of the package's maximum allowable variation (MAV), with at least 100 divisions. FloorCheck shows the MAV for each product.
A scale used to set the weight printed on a label may need to be approved for commercial use (NTEP in the United States) under state law. A scale used only for in-plant quality checks may not. Ask your state weights and measures office.
Keep your scale calibrated and verify it daily with a check weight. FloorCheck's scale verification check is built for this.