Connect Scales to Square Point of Sale
Connect and troubleshoot your supported CAS PD-2 USB scale with Square Point of Sale.
Before you get started:
Make sure your Square app is up to date. The latest version of the Square Point of Sale app is required to connect to the scale.
Ensure you set up Items to sell by weight.
Display the National Measurement Institute certified sticker on your Square hardware.
Make sure you have read and understand the regulations of selling by weight on the NMI website. It is your responsibility to ensure that you follow all of these regulations.
Note: The CAS PD-2 USB scale is not supported with Square for Retail, Square for Restaurants, Square Invoices and Square Appointments apps.
National Measurement Institute Certified Sticker
Square has produced a sticker indicating the scale connection to our Point of Sale has been certified by the National Measurement Institute (NMI). When you purchase a USB scale or the cables through Square Shop, you will have been supplied a sticker with the NMI certification number.
You must clearly place this sticker on the device running the Square Point of Sale app (i.e. Square Stand, Android tablet/smartphone or Square Terminal). The sticker helps NMI field inspectors identify that Square has fulfilled all compliance regulations for the certification from the National Measurement Institute. Contact Square Support if you need a complimentary replacement sticker.
Important to note: in order to be compliant for the Certification, you need to connect a physical printer if you're using a scale with Square Stand, Square Register or Android device.
Supported Hardware
The CAS PD-2 USB scale is compatible with:
| Hardware | Compatibility |
|---|---|
| Square Stand* | ✔️ |
| Square Terminal with Hub | ✔️ |
| Square Register | ✔️ |
| Android with Square Reader | ✔️ |
| iOS with Square Reader | ✖️ |
*This USB scale is supported with the following Square Stands:
Square Stand (2nd generation)* for iPad (2021, 2020, 2019), 10.5" iPad Air (2019), iPad Pro 10.5”
Square Stand (1st generation)* for iPad (2021, 2020, 2019), 10.5" iPad Air (2019), iPad Pro 10.5”
Square Stand (1st generation)** for iPad (2017, 2018), iPad Pro 9.7", and iPad Air (1, 2)
Not sure which Square Stand model you have? Learn how to identify your Square Stand Model.
For a list of all compatible hardware by device, check out our supported third-party hardware accessories.
Connect Your USB Scale
For Square Stand (2nd generation), a successful connection requires the following:
- USB cable for your Square Stand model *
- Serial to HID adapter (only for Square Stand for iPad (2017, 2018), iPad Pro 9.7”, and iPad Air (1, 2))
- Null modem adapter/null modem cable
- National Measurement Institute certified sticker
*Square Stand cable can be purchased through Square Shop. If you purchase the CAS PD-2 USB scale for your Square Stand model from Square Shop, the cable is included.
To connect the CAS PD-2 scale to your Square Stand for iPad (2021, 2020, 2019), 10.5” iPad Air (2019), iPad Pro 10.5”:
- Plug the 9-pin RS-232 male side of the FTDI cable into the female end of the null modem adapter/null modem cable.
- Plug the male end of the null modem adapter/null modem cable into the port on your scale.
- Plug the male side of the USB-A into a hardware hub for the Square Stand.
To connect the CAS PD-2 scale to your Square Stand for iPad (2017, 2018), iPad Pro 9.7”, and iPad Air (1, 2):
- Plug the 9-pin male end of the serial-to-HID adapter into the female end of the null modem adapter/null modem cable. Then plug the male end of the null modem adapter/null modem cable into the port on your scale. To keep the adapter firmly connected, twist the security screws into place.
- Plug the micro-USB end of the cable into the adapter, and plug the USB-A side of the cable into the USB accessory hub on Square Stand.
To check the connection of your scale:
- Open the Square Point of Sale or Square Retail POS app and tap ≡ More.
- Tap Settings > Hardware > Scales.
- The connected scale should appear in the app menu as USB Scale. If you do not see the scale name appear under Settings, check the connection between your scale and relevant cables, or accessories.
To disconnect the scale, just unplug the scale’s cable from your device.
For Square Register, a successful connection requires the following:
- USB cable (1.5 m) included with USB scale via Square Shop
- Null modem adapter/null modem cable (2 m)
- National Measurement Institute certified sticker
For Square Terminal* and Android**, a successful connection requires the following:
- D-sub to USB-A cable
- Null modem adapter/null modem cable
- National Measurement Institute certified sticker
*Square Terminal also requires the Hub for Square Terminal.
**Requires either a micro USB on the go (OTG) adapter or USB-C OTG adapter depending on the port on your Android device.
- To connect the CAS PD-2 scale to your Square Terminal:
- Plug the 9-pin male end of the D-sub cable into the female end of the null modem adapter/null modem cable. Then plug the male end of the null modem adapter/null modem cable into the port on your scale. To keep the adapter firmly connected, twist the security screws into place.
- Insert the USB-A male end of the D-sub cable into the Hub for Square Terminal.
- To check the connection, open the Square Point of Sale or Square Retail POS app and tap ≡ More > Settings > Hardware > Scales.
- The connected scale should appear in the app menu as USB Scale.
To connect the CAS PD-2 scale to your Android device:
- Plug the 9-pin male end of the D-sub cable into the female end of the null modem adapter/null modem cable then the male end of the null modem adapter/null modem cable into the port on your scale. To keep the adapter firmly connected, twist the security screws into place.
- Insert the USB-A male end of the D-sub cable into the female end of the OTG adapter.
- Insert the male end of the OTG adapter into the USB port on your Android device.
- To check the connection, open the Square Point of Sale or Square Retail POS app and tap ≡ More > Settings > Hardware > Scales.
- The connected scale should appear in the app menu as USB Scale.
Note: The Square Point of Sale app can only connect to one scale at a time.
Troubleshoot Your USB Scale
Confirm you’re using the CAS PD-2 USB Scale with supported iPads with Square Stand, Square Terminal, or an Android smartphone or tablet.
Make sure your Square app is up to date. The latest version of the Square app for Android is required to connect to the scale.
Ensure you’ve correctly set up Items to sell by weight.
Check that you have a secure connection between your scale, cables, adapters, and any additional connected accessories.
Make sure you’re using the correct cables for your scale. The cable is included in the scale but if you need a replacement, purchase a Square Stand (1st generation) USB cable or Square Stand (2nd generation) accessory hub and Square Terminal or Android USB cable via Square Shop.
Note: The CAS PD-2 USB scale needs to be in ECR-5 mode to work properly.
To ensure your CAS PD-2 scale is set up in the right ECR (Extended Control Register) mode:
With the scale turned off, hold the T key and turn the scale on.
When Ecr SEt appears, release the T key.
The display will show tyPE X, where X is the current type setting. Use the * key to select type 5.
Press the 0 key to save.
Turn the scale off and then back on again.
Contact CAS Support
If you have tried all troubleshooting options above and your scale is still not connecting, reach out to CAS Support for further in-depth troubleshooting. Please provide CAS Support with the context of the situation as well as all of the troubleshooting steps already attempted—providing this information will give them all the information needed to assist you, without repeating previous troubleshooting methods.
For technical support for CAS scales, contact your local retailer where you purchased your CAS scale. For support of any CAS product purchased online, call CAS Support at (07) 3267 7767.
Label Printing Scales
We also support label printing scales if you don't need your scale connected directly to your Square Point of Sale.
Learn more about setting up items by weight, barcode formatting, and Set up your barcode label printing scale.