Quick answer: The drawer connects to the receipt printer, not to Erply, and the printer fires it. Erply's hardware documentation refers to a 24V cash drawer — which matters, because a 24V drawer on a 12V printer port is the most common reason a drawer will not open.
So the decision is made when you choose the printer, not the drawer. Our NBCD-460 (460mm, standard counter) and NBCD-410 (410mm, tight counter) are specified to match the printer they ship with — tell us the printer and we match the voltage before it leaves.
How the drawer is actually wired
A POS cash drawer is a passive box: a solenoid, a latch and a spring. No intelligence, no network, no software. A voltage pulse arrives on its RJ11 port, the coil pulls the latch, the spring throws the drawer open. That is the entire mechanism.
The pulse comes from the receipt printer. The printer has a drawer port on the back, and when the POS prints a receipt it also sends the open-drawer command, which the printer converts into that pulse.
Erply follows this standard arrangement — their hardware documentation covers the drawer alongside the printer and references drawer setup through the printer's control signals. The exception in their list is the Star mPOP, which is a combined printer-and-drawer unit connecting over Bluetooth; that is a single product rather than two, and the wiring question does not arise.
The practical consequence: if the printer is not printing, the drawer cannot open, and nothing you change in Erply will help. On Erply specifically, that means checking the microservice status indicator before you suspect the drawer.
The 24V detail, and why it is not a NETBYE specification
Erply's documentation refers to a 24V cash drawer. It is worth being precise about what that does and does not tell you.
The voltage is set by the printer, not by the POS software. Erply's tested printers are mostly Epson and Star units, whose drawer ports commonly run at 24V — so a 24V drawer is the natural pairing in that context. It is a consequence of their hardware list, not a requirement Erply imposes on you.
What you actually have to do is match the two ends:
| 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 middle row is the one that produces support calls months after installation, because it degrades rather than fails outright. A drawer that worked at commissioning and is intermittent by week six looks like a faulty drawer; it is usually a voltage mismatch working against a spring that has lost its first stiffness.
Our 80mm printers and our drawers are matched when bought together. If you are adding drawers to printers you already own — Epson or Star included — tell us the printer model and we will confirm the port voltage before you order.
When the drawer opens
On most systems the drawer opens on a cash or cheque sale and stays shut on a card sale, since the card terminal handles the money. Make sure staff know how to trigger a no-sale open for giving change, rather than leaving the drawer unlatched — an unlatched drawer is both a shrinkage problem and an audit problem, and it hides a hardware fault rather than fixing 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 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 Erply: buy the drawer with the printer so we can match voltage. Confirm the printer model has an RJ11 drawer port — not every compact 58mm printer does. If you are standardising on Erply's tested printers, tell us which model and we will supply drawers matched to it.
Frequently asked questions
Does the cash drawer connect to Erply or to the printer?
To the printer, by RJ11 cable into the drawer port. Erply sends the print job; the printer fires the drawer.
Does Erply require a 24V drawer?
Erply's documentation refers to a 24V drawer, but the voltage is determined by your printer's drawer port rather than by Erply. Match the drawer to the printer: 12V to 12V, 24V to 24V.
My drawer will not open.
In order: is the microservice indicator green? Does the printer print? Is the cable in the drawer port rather than a network port? Is the voltage matched? The first two account for most cases.
Can I use a cash drawer without a receipt printer?
Only with a USB-trigger drawer, which has its own controller and presents to the host as a device in its own right. That is a different product and worth specifying deliberately for a receipt-less counter.
Will any drawer work with any printer?
Physically yes, electrically no. The RJ11 connector is standard; the voltage is not.
What about the Star mPOP?
That is a combined printer and drawer in one unit connecting over Bluetooth, so there is no separate drawer to wire. It is a different product category from a standard printer plus drawer.
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 Erply-specific parts, including the 24V reference and the mPOP arrangement, are drawn from Erply's published wiki; the point that voltage is set by the printer rather than by Erply is our reading of it, not a statement from Erply. Confirm current details with Erply, and 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 Erply POS is covered here:
And if you are comparing across POS software, the same hardware for other systems: