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Pair a Bluetooth Card Reader (PAX D135)

The PAX D135 is a small Bluetooth card reader that works with one iPad at a time. Unlike the countertop PAX terminals, it isn't on your store's Wi-Fi and the web register can't use it: the iPad talks to it directly, and the iPad app runs the card payment. Pairing takes about five minutes per reader.

What you need:

  • The D135, charged, and its serial number (on the label on the back).
  • An iPad running the Ayuna POS app that has already registered at the store (see Set Up the Register).
  • A store manager's login: binding a reader to a register is a manager setting.
  • Your organization's Finix merchant onboarding complete. Binding a D135 also sets up the reader's own payment key with Finix, so this has to be done first; if it isn't, the binding is refused and the message says so.

1. Add the reader in Payment Devices​

  1. In the web app, open Point of Sale → Payment Devices, pick the store, and click Add Device.
  2. Choose the model PAX D135, enter the serial number from the label, and give it a name you'll recognize on the floor (for example "Register 2 reader").
  3. Save. The row shows an iPad only badge and the reader is active at once. A D135 has no activation code to type in and no standalone mode: both of those belong to countertop terminals.

2. Bind it to the iPad​

On the iPad that will use the reader:

  1. Open Settings → Register.
  2. Under Card reader, choose the D135 by name. The binding is saved on the server, and the reader's payment key is issued at the same time.
  3. Turn the reader on and keep it within a few feet of the iPad. The app finds it over Bluetooth and connects. The first connection can take several minutes: the reader downloads firmware and parameter files from the iPad, and the row under Card reader shows the progress. Leave the reader on and next to the iPad, and don't start a sale until that row says the reader is connected. If it doesn't connect on its own, tap Connect reader. With several readers in range, the app lists the devices named like a reader (D135…); pick yours, and the choice is remembered. Show all Bluetooth devices lists everything the iPad can see, in case the reader advertises under another name.

A D135 binds to one iPad. If another register already holds it, the app says which one; unbind it there first. A D135 never binds automatically, even when it's the store's only reader.

3. Take a test payment​

Ring a small sale and take it by card. The card prompt appears on the iPad and the reader lights up to take the tap or insert. The payment records like any other card sale, and the receipt prints on the register's Epson printer. The D135 has no printer of its own, so Print on Card Terminal never appears after a sale it ran. With no receipt printer paired, reprint the receipt from Transactions once one is.

The reader's lights​

  • Solid or slow-blinking blue: connected to the iPad and idle.
  • Four lights across the top during a payment: reading the card. Hold the card until the lights finish.
  • Blinking red, or no light: the battery is low or the reader is off. Charge it; the app reconnects on its own when it comes back.

Updating the reader​

Reader updates are pushed from the iPad over Bluetooth. Settings → Register shows, under the bound reader, Check reader firmware (the version the reader reports) and Update reader. Run an update between sales, keep the reader next to the iPad, and don't start a payment until it finishes; an update takes a few minutes.

Load payment keys asks the reader to fetch its card keys from the payment processor. A new reader does this on its first connection; use the button only if a payment reports that the reader has no keys, or after the reader has been moved between a test and a live setup.

If an iPad or a reader goes missing​

Either one leaving the building means the pairing has to end, because the reader's payment key goes with it.

  • The iPad is lost or replaced. On the web app, open Payment Devices, find the reader, and click Revoke key. That disables the reader's payment key immediately; a lost iPad can no longer take payments with it. Then, on the store's page (Store Management → the store → Registers), use ⋯ → Release device on the register the lost iPad held, so the replacement iPad can claim it. Bind the reader to the new iPad under Settings → Register, which issues a fresh key.
  • The reader is lost. On the iPad it was bound to, open Settings → Register and set Card reader to No reader bound. That disables the key as well. Deactivate the reader in Payment Devices so it stops being offered; deactivating also unbinds it from any register and disables its key, so it is a safe step on its own.
  • The reader moves to another store. Move it in Payment Devices. The move unbinds it from its registers at the old store and disables its key; bind it again at the new store.
  • You're not sure which. Revoke key is the safe first step either way: nothing can pay with the reader until a manager binds it again.

Troubleshooting​

  • "Finix merchant onboarding is not complete" when binding. Your organization's payment processing isn't set up yet; see Configure Payment Processing.
  • The app can't find the reader. Make sure it's charged and on, and that Bluetooth is on for the iPad. Only the iPad the reader is bound to connects to it.
  • "The reader stopped answering while connecting." An update was interrupted. Turn the reader off and on again, wait for its light, then tap Connect reader once and let the progress finish.
  • "A card payment on this cart is still pending." A payment started on the reader and nothing reported how it ended, so the cart can't be voided around it. Tap Resolve on that banner: the app ends the attempt, asks the processor whether anything was charged, returns it if so, and then voids the cart. A payment the processor has not settled within a few minutes is ended on its own.
  • The card screen says the register has no active key. The key was revoked, or the reader was bound to a different iPad since. A manager binds the reader to this iPad again under Settings → Register.
  • "RKI environment mismatch" on the first payment. The reader was keyed for a different Finix environment (a sandbox test reader on a live account, or the reverse). It needs to be re-keyed by Finix; contact support.