Quick answer: The cash drawer does not connect to eHopper. It connects to the receipt printer, by an RJ11 cable, and the printer fires it. In eHopper you only tell the software which printer the drawer is behind — Settings → Cash Drawer, tick the printer, press test.
That makes the printer, not the drawer, the part you have to get right. And the one specification that actually decides whether the drawer opens is voltage: the printer's drawer port and the drawer's solenoid must match. Our NBCD-460 (460mm, standard counter) and NBCD-410 (410mm, tight counter) are both specified to match the printer you buy them with.
How the drawer is actually wired
Almost every POS cash drawer in the world is a passive box with a solenoid in it. It has no intelligence, no network connection and no software. When it receives a voltage pulse on its RJ11 port, a coil pulls a latch and a spring throws the drawer open. That is the whole mechanism.
The pulse comes from the receipt printer. The printer has a drawer port on the back, and when the POS sends a receipt it also sends the ESC/POS “open drawer” command — the printer converts that into the voltage pulse.
eHopper follows this standard arrangement. Their setup guidance is to connect the drawer to a working printer, then in the app go to Settings → Cash Drawer, select the checkbox next to the printer that the drawer is connected to, and use the test function — if the drawer opens, it is set up.
Read that sequence again and note what it implies: if the printer is not working, the drawer cannot work, and no amount of configuration in eHopper will change that. Get the printer printing first. Always.
The Android case: a network printer still fires a physically-attached drawer
This trips people up on tablet-based tills, so it is worth being explicit.
When eHopper runs on an Android tablet, the printer is a network device — it sits on Ethernet and the tablet finds it over Wi-Fi. It is tempting to conclude that the drawer must also be network-connected, or that it plugs into the tablet somehow.
It does not. The drawer still plugs into the back of the printer with an RJ11 cable, exactly as it would on a Windows till. The chain is: tablet → Wi-Fi → router → Ethernet → printer → RJ11 → drawer. The only wireless link is between the tablet and the printer.
The practical consequence for a store layout: the drawer has to be within cable reach of the printer, not of the tablet. If you were planning to carry the tablet around the shop and keep the drawer at the counter, that works fine — but the printer must stay at the counter with the drawer.
Voltage: the specification that decides everything
This is the failure we see most, and it is entirely avoidable at the ordering stage.
Drawer solenoids are built for a particular voltage, usually 12V or 24V. Printer drawer ports output a particular voltage, usually 12V or 24V. They have the same connector, so any drawer will physically plug into any printer. Whether it opens is another matter.
| Combination | Result |
|---|---|
| Matched (12V→12V or 24V→24V) | Opens crisply, every time |
| 12V printer → 24V drawer | Usually will not open, or opens while the spring is new and stops weeks later |
| 24V printer → 12V drawer | May open, running the coil over its rating — risks overheating over time |
The second row is the nasty one, because it fails gradually. A drawer that opens reliably during installation and intermittently a month later looks like a faulty drawer. It is usually a voltage mismatch working against a spring that has lost its first stiffness.
If you buy the printer and drawer from us together, we match them. If you already have printers and are adding drawers, tell us the printer model and we will confirm the drawer port voltage before you order.
Cash-only mode, and when the drawer opens
On most POS systems the drawer opens automatically on a cash or cheque sale and stays shut on a card sale, because the card terminal handles the money. eHopper follows that pattern, and it is worth confirming during setup that staff know how to trigger a “no sale” open for giving change, rather than leaving the drawer on the latch.
One practical note for busy counters: a drawer that is opened by hand rather than by the solenoid — because someone left it unlatched — is a shrinkage problem and an audit problem. If the drawer is not opening reliably on its own, fix the cause rather than working around it.
Sizing: 410mm or 460mm?
460mm is the standard full-size drawer and the right default for a retail counter handling a normal mix of notes and coin. 410mm is for counters where space is genuinely tight — a kiosk, a coffee bar, a market stall — and it takes fewer note compartments, which matters more in currencies with many denominations in circulation.
NETBYE models
| Model | Width | Note |
|---|---|---|
| NBCD-410 | 410mm | Compact, for a tight counter. 4- or 5-position bill trays, 8-position coin tray. Rated to 1.5 million cycles. |
| NBCD-460 | 460mm | Standard full size. Up to 6 bill compartments, single- or double-row coin tray. |
Both have the standard RJ11 drawer port and a manual key override. Browse cash drawers.
Ordering advice for eHopper: order the drawer with the printer so we can match the voltage. Confirm the printer model has an RJ11 drawer port — not every compact 58mm printer does. If the till is Android-based, remember the drawer sits with the printer, not with the tablet. See the eHopper receipt printer guide for choosing between the USB and LAN variants.
Frequently asked questions
Does the cash drawer connect to eHopper or to the printer?
To the printer. eHopper's own setup is to connect the drawer to a working printer, then tick that printer under Settings → Cash Drawer so the software knows which one to fire.
My drawer will not open.
Work through it in this order: does the printer print? If not, fix that first — the drawer cannot open without it. If the printer prints, check the RJ11 cable is in the drawer port and not a network port. Then check voltage matching. Then use eHopper's test function under Settings → Cash Drawer.
Can I use a cash drawer without a receipt printer?
Only with a USB-trigger drawer, which contains its own controller and appears to the host as a device in its own right. That is a different product from a standard passive drawer and is worth specifying deliberately if you run a receipt-less counter.
Will any drawer work with any printer?
Physically yes, electrically no. The RJ11 connector is standard but the voltage is not. Match 12V to 12V and 24V to 24V.
How does this work on an Android tablet, where the printer is on the network?
The same way. The drawer plugs into the printer by RJ11; the tablet talks to the printer over the network. The drawer needs to be within cable reach of the printer, not the tablet.
Can the drawer open on card sales too?
That is a POS setting rather than a hardware one. Most retailers leave it off, since the card terminal takes the payment and there is no cash to put away.
A note on this guide. The drawer side above — solenoid behaviour, RJ11 wiring, voltage matching, cycle ratings — is what we know from the products we supply, and it holds for any POS where the printer fires the drawer. The eHopper-specific parts, including the Settings → Cash Drawer step and the test function, are drawn from eHopper's published guides. Menus change between releases, so confirm current details with eHopper. If something here did not match your installation, tell us and we will correct this page. We would rather publish something accurate than something impressive.
Get pricing
NETBYE supplies distributors, system integrators and retailers worldwide. Our cash drawers are built by our partner factories in Shenzhen and sold under our own model range — we handle specification, quality control and support, so you deal with one supplier rather than several factories. Direct wholesale pricing, low MOQ on first orders, and OEM/ODM covering branding and tray configuration.
Tell us which printer you are pairing it with, how many tills, what quantity and which country, and you will get an accurate quote in one reply — with the voltage already matched. Request a quote.
Related guides
These guides form a set. If you are specifying a complete till, the other hardware for eHopper POS is covered here:
And if you are comparing across POS software, the same hardware for other systems: