Cloud vs Bluetooth vs USB: choosing a card terminal integration
Three ways to connect a till to a card terminal, what each costs you in support calls, and why cloud integration is the easiest to roll out across many shops.
Once you decide your till should drive the card terminal, you still have to choose how the two talk. There are three common answers, and the right one depends less on the technology than on how many shops you support.
1. Cable (USB or serial)
The terminal plugs into the till PC and speaks a vendor protocol over the cable.
- Good: works without internet between till and terminal; very low latency.
- Bad: needs a driver for every terminal model and every operating system; the terminal is tied to one till; a new PC or a Windows update can break it.
2. Bluetooth or local network
The till pairs with the terminal over Bluetooth, or finds it on the shop's Wi-Fi.
- Good: no cable across the counter; the terminal can move a little.
- Bad: pairing drops, phones and tablets go to sleep, and the till needs an SDK for each terminal brand. Local-network discovery fails on guest Wi-Fi or when the router changes.
3. Cloud
The till calls an HTTPS API; the terminal keeps a connection to the same service. Neither needs to find the other.
- Good: no drivers, no SDK and no pairing. Any till platform works, including web tills and tills hosted in a data centre. One till can drive many terminals, and a terminal can be anywhere with internet: at a table, in a delivery van or at a drive-through window.
- Bad: both the till server and the terminal need internet. A payment takes the round trip to the service, which is normally well under a second on top of the card authorisation itself.
Which one should you pick?
| Cable | Bluetooth / LAN | Cloud | |
|---|---|---|---|
| SDK or driver per terminal | Yes | Yes | No |
| Works with web or hosted tills | No | No | Yes |
| One till, many terminals | Hard | Hard | Yes |
| Needs internet | Terminal only | Terminal only | Till and terminal |
| Typical support issue | Drivers | Pairing | Connectivity |
If you support one shop with one fixed till, a cable is fine. If you sell POS software to many businesses, or your till runs in a browser, cloud integration removes most of the support calls, because there is nothing to install on the till and nothing to pair.
How Revoluno does cloud integration
With the Revoluno Cloud API, Sunmi and Nexgo terminals run the Revoluno app in cloud mode and long-poll the service for work. Your till sends a checkout to a specific terminal, and the result comes back as a signed webhook. Card data stays on the terminal, which authorises with the payment switch itself.
Read how to set up a Sunmi or Nexgo terminal next, or go straight to the API reference.