Paloma365

English

Русский

English

Русский

Appearance

Hardware troubleshooting — Paloma POS 2 ​

This article is about Paloma POS 2 — the new Paloma register app for a tablet, POS terminal, or Windows device. If you are not sure which product you have, start with «How to tell you have Paloma POS 2». This article covers what to do when hardware stops responding: USB devices on Android (reconnecting and access), network and subnets (a device on a factory IP in another subnet is invisible), availability of network devices (printers, POS devices), the second screen (customer display), and a general "device not responding" checklist. For printers and the print queue see «Printers»; for scales and barcode scanners see «Scales and barcodes».

Overview ​

  • Know how the device is connected. The register talks to hardware three ways: over a USB cable (on Android through an OTG adapter, on Windows directly), over the local network (LAN) by IP address, and through the built-in port of a Sunmi/Valor terminal. The connection type decides what to check on a fault.
  • USB on Android is detected automatically. Plug in the cable — the register shows the device in the «Available USB devices» card. No card, or an empty card, is the signal to check the OTG adapter, power, or access.
  • A network device must be on the same subnet. If a printer or terminal is still on a factory IP from a different network, the register cannot see it. The register can move a printer into your network — over USB or (on Windows) automatically.
  • Device availability is on one screen. Under «Diagnostics» there is «Monitoring» — it shows whether POS devices and network printers can see each other.
  • Printing never blocks the register. Jobs go to a queue and print in the background, so an unreachable printer never freezes the register. See «Printers» for the queue.

USB devices on Android (reconnecting) ​

On Android a USB printer connects through an OTG adapter. The register detects the device itself and shows it in the printer card.

  1. Open «Settings» → «Hardware» → «Print» → «Hardware and printers», open the printer card, and under «Connection» choose USB.
  2. Below the «Choose USB device» button, the «Available USB devices» card appears. Three states are possible:
    • Rows like «VID 0x… • PID 0x… • …» — Android sees the device and access is granted. If printing still fails, the cause is further down the chain (wrong printer selected, wrong paper width, out of paper, head lever up).
    • Empty — the register shows «No USB devices detected — check OTG adapter and printer power». The device did not reach the register: check the OTG adapter and cable, printer power, and OTG support on the tablet.
    • No card — USB is not selected in the connection, or the device was detected as a built-in Sunmi/Valor printer (a different path).
  3. If a pop-up «Allow access to the USB printer and try printing again» appears, grant USB access and retry the test print.

How to reconnect a USB device:

  • Unplug and re-plug the USB cable (or OTG adapter) — the «Available USB devices» card refreshes.
  • Make sure the OTG adapter and cable carry data, not just power. Quick test: plug a regular USB keyboard or mouse through the same adapter — if they do not work, the adapter or the tablet's OTG support is the limit, not the app.
  • Make sure the printer has its own power (most receipt printers have their own power supply).
  • After reconnecting, tap «Choose USB device», select the printer again, then «Test print».

Devices on another network (subnet) ​

Network printers and terminals often ship from the factory with a fixed IP from a foreign subnet (for example 192.168.123.100 when your network is 192.168.0.x). In that case auto-discovery finds nothing and printing by IP fails.

In the printer card, when the device is not found, the register shows a «Printer not found?» block explaining that the printer is probably on a factory IP in another network, and offers two ways to move it into your network.

Relocate over USB (Android and Windows) ​

  1. Connect the printer to the register device with a USB cable.
  2. In the «Printer not found?» block tap «Relocate over USB». If the printer is not on USB, the register prompts: «Connect the printer to this device with a USB cable and try again.».
  3. In «What printer is this?» pick the vendor — so the register sends the right command.
  4. In «New address» the register suggests an address on your network. Tap «Relocate».
  5. While it reconfigures, the register shows «Relocating printer… (~10 s)», then «Printer relocated to …». On failure — «Could not relocate the printer. Check the USB connection and try again.».

Find on another network (Windows only) ​

On Windows the register can find the printer in common factory networks and move it itself.

  1. In the «Printer not found?» block tap «Find printer on another network».
  2. In «Find printer on another network?» the register warns that it will briefly join the printer's factory networks, that admin rights are needed, and that it may take up to a minute. Optionally set «Subnet to search (optional)» (for example 192.168.55). Confirm with «Find».
  3. While searching, the register shows «Searching for your printer on other networks…». On success — «Printer found and relocated to …».
  4. If nothing is found — «Printer not found on common factory networks.». If rights were missing — «Could not change network settings. Run the app as administrator and try again.».

During the search the register briefly switches to a fixed address and returns to automatic (DHCP) after a restart. To restore the automatic IP manually, use «Restore automatic IP (DHCP)».

Availability of network devices (monitoring) ​

To see whether devices can reach each other on the network, there is a dedicated screen.

  1. Open «Settings» → «Diagnostics».
  2. Open the «Monitoring» row (subtitle — «Check whether POS devices and network printers see each other»).
  3. If monitoring is off, the register shows the hint «Monitoring is off. Turn it on to check the availability of POS devices and network printers.». Turn on the «Enable monitoring» switch.

With monitoring on, the screen shows:

  • «Cloud connection» — whether the register has a link to the server.
  • «POS devices» — the account's other registers, each with a status: «On the local network», «Cloud only», or «Not visible». If there are none — «No registered devices in the account yet.».
  • «Network printers» — the status of each: «Reachable» or «Unreachable». If none are configured — «No network printers configured.».

The «Refresh» button runs a full re-probe (showing «Checking availability…»). If a device or printer reads «Not visible» / «Unreachable», it is not on the same network as the register or is powered off: check power, cable or Wi-Fi, and the subnet.

The second screen (customer display) does not show ​

If the customer display is on but the second screen is blank, or the register says the screen is not detected, start with the built-in diagnostics.

  1. Open the customer-display settings and tap the «Check displays» button.
  2. The «Displays detected by the system» dialog opens. Read it top to bottom:
    • Rows like «Monitor …: … — primary: …, usable: …» — the screens the system sees. The second screen should be in the list and be usable.
    • «The system reports no displays.» — the system sees no screens at all: check the cable and Extend (not Duplicate) mode.
    • «Bridge state: shown on a second screen» — the customer screen is working.
    • «Bridge state: hidden (no second screen mounted)» — the system finds no suitable second screen.
    • «Bridge state: unsupported on this build» — a second screen is not available on this device; use a separate device over the network (see «Customer display»).
    • «Last attempt error: …» — what exactly prevented the screen from showing last time.
  3. When contacting support, pass these details along verbatim — they show exactly where the chain breaks.

Important: remote access (AnyDesk, TeamViewer). During a remote-access session, the remote-control program creates a "virtual" screen, and the register deliberately ignores it — otherwise the customer screen would open on the remote operator's side instead of the register's working screen. So if the second screen is "not detected" during a remote support session, that is normal, not a fault. Check the second screen after the remote-access session has ended.

"Device not responding" checklist ​

Work from simple to complex:

  1. Power. The device is on, indicators are lit, the printer has paper and the cover is closed.
  2. Connection type. Determine how the device links to the register: USB, network (LAN), or the built-in port. For USB, check the cable and adapter; for network, check the IP address and subnet.
  3. USB. Re-plug the cable, check the «Available USB devices» card (Android). Grant access if the register asked.
  4. Network. Make sure the device and the register are on the same network. If the device is on a factory IP in another subnet, relocate it («Relocate over USB» or «Find printer on another network»).
  5. Monitoring. Open «Diagnostics» → «Monitoring» and read the device status. Tap «Refresh».
  6. Test. For a printer, run «Test print» in its card or «Test all printers» — that shows whether commands reach the hardware.
  7. Exact text. If an error appeared, note it verbatim. It points to where the break is (power, paper, cable, network, or address).

Common problems ​

  • «No USB devices detected — check OTG adapter and printer power» — Android does not see the device. Check the OTG adapter and cable (does it carry data), printer power, and OTG support on the tablet.
  • «Allow access to the USB printer and try printing again» — the device requested USB access. Grant access in the pop-up and retry.
  • «Write fault — reconnect the printer» — a link failure with the USB device. Unplug and re-plug the cable, then retry.
  • «Cannot reach the printer at … — check the IP address and subnet» — the network device is unreachable at that IP. Make sure it is on and on the same subnet; relocate it into your network or update the IP if needed.
  • «The printer at … refused the connection — make sure the printer is on and accepts printing over TCP» — the device is on the network but does not accept the connection on that port. Check the port (usually 9100 for printers) and the device settings.
  • «Network unavailable — check the Ethernet cable or WiFi» — the register device itself lost the network. Check the tablet/terminal network connection.
  • «Printer not found?» — the device is not found by auto-discovery. It is most likely on a factory IP in another network. Relocate it with «Relocate over USB» or (on Windows) «Find printer on another network».
  • «Printer not found on common factory networks.» — the search of other networks did not find the device. Check power and cable, optionally set the subnet manually and retry.
  • «Could not change network settings. Run the app as administrator and try again.» — on Windows the app lacked rights. Run it as administrator and retry.
  • «Could not relocate the printer. Check the USB connection and try again.» — the USB relocation did not finish. Check the USB cable and retry.
  • «Not visible» / «Unreachable» — a device status in «Monitoring». The device is not on the same network as the register or is off: check power, network, and subnet, then tap «Refresh».

FAQ ​

The register does not see the USB printer on the tablet. Where do I start? ​

Open the printer card, choose USB under «Connection», and look at the «Available USB devices» card. If it is empty («No USB devices detected…»), re-plug the OTG adapter and cable and check printer power. Quick adapter test: plug a keyboard or mouse through it — if they do not work, the adapter or tablet is the problem, not the app.

What does "device on another subnet" mean? ​

It means the device has a fixed IP from a foreign network (for example a factory one), and the register on your network cannot see it. Switch the device to automatic IP (DHCP) or, for a printer, use «Relocate over USB» or (on Windows) «Find printer on another network» — the register moves the printer into your network itself.

How do I check whether devices see each other? ​

Open «Settings» → «Diagnostics» → «Monitoring» and turn on «Enable monitoring». The screen shows the cloud connection, POS-device statuses («On the local network» / «Cloud only» / «Not visible»), and network printers («Reachable» / «Unreachable»). The «Refresh» button re-checks everything.

The printer prints intermittently or "drops out". What is this? ​

Usually an unstable link. For USB it is a bad cable or adapter: reconnect, and on «Write fault — reconnect the printer» replace the cable. For the network the printer comes and goes: check Wi-Fi/cable, and if the IP changes often enable network printer auto-discovery (see «Printers»).

The device does not respond and there is no error text. What now? ​

Run the "device not responding" checklist top to bottom: power → connection type → USB → network and subnet → monitoring → test print. Most steps show a status or message that points to the break. If you reach the end and the cause is unclear, have your account name, device model, and connection type ready and message us here — a specialist will join.