Adding counter PCs on the shop network

With MediPOS Offline, each extra billing counter is a Windows PC that connects to the main PC over your shop network (LAN). The data stays on the main PC; a counter PC only shows it and prints its own receipts. This guide is for the owner setting up a second or third counter: installing it in counter mode, the main PC's address, the firewall and private network settings, and what happens when the main PC is switched off.

Before you start

• The main PC is installed and working, with Counter PCs on the shop network will connect to this PC ticked. If you did not tick it, run the installer again on the main PC, choose Main PC of the pharmacy (keeps the data) and tick the box. Your data stays as it is.
• Both PCs are connected to the same router or switch, by cable or Wi-Fi.
• The main PC's network is set to Private in Windows. The installer opens port 8321 in Windows Firewall for private (and office domain) networks only, so counters cannot connect while Windows treats the shop network as Public.

To check it on Windows 11, open Settings → Network & internet → Ethernet (or Wi-Fi and then your network) and set Network profile type to Private network. On Windows 10 it is Settings → Network & Internet → Status → Properties → Private.

How to find the main PC's address

1. On the main PC, search for cmd and open Command Prompt.
2. Type ipconfig and press Enter.
3. Note the IPv4 Address of the adapter on the shop network, for example 192.168.1.10.

Ask whoever set up your router to reserve this address for the main PC (routers call it DHCP reservation or address binding). Otherwise, after the router restarts when the power comes back, the main PC may get 192.168.1.14 and every counter loses it.

You can test the connection before installing anything. On the counter PC, open a browser and go to http://192.168.1.10:8321. If the MediPOS sign-in page appears, the network and firewall are ready.

How to install a counter PC

1. Run the same MediPOS installer on the counter PC and choose Yes when Windows asks for permission.
2. On How is this PC used?, choose Counter PC (connects to the main PC on the shop network).
3. In Main PC address (e.g. 192.168.1.10): type the address only, without http:// or a port. If you leave it empty, the installer stops with "Enter the main PC's address."
4. Click Install, then Finish with Open MediPOS ticked.
5. MediPOS shows Connecting to 192.168.1.10… and then the sign-in screen, with Server: 192.168.1.10 at the bottom.
6. Each cashier signs in with their own account. The owner adds staff under Administration → Team.

What a counter PC stores

So when counter 2 sells the last strip of Augmentin 625, counter 1 sees the stock drop at once: they use the same database. A counter PC that breaks is replaced by installing MediPOS on another computer, with nothing to restore.

How bill numbers work with several counters

All counters share one number series per document type, handed out by the main PC's database. Counter 1 prints INV-000245 and counter 2 the next bill, INV-000246. Two cashiers finishing a bill at the same second never get the same number, and a bill that fails gives its number back, so the series has no gaps. There is no separate series per counter PC; to see who made a bill, look at the Cashier on the receipt and in the sale.

What happens if the main PC is off

Counter PCs keep no copy of the data, so they cannot bill while the main PC is off or unreachable.

• When a counter opens MediPOS, it shows "Cannot reach the MediPOS server at 192.168.1.10. Check that the main PC is on and connected to the network." with a Try again button.
• If the connection drops while a cashier is completing a bill, the POS shows "Connection problem — press F12 again. The sale will not be duplicated." Once the main PC is back, press F12 again. MediPOS recognises it as the same bill and records it once.

During load-shedding the main PC, the router and any network switch all need power. A counter laptop on battery cannot bill if the router has gone dark. One UPS for the main PC and the router is usually enough.

Rules and tips

• If the main PC's address changes, run the installer again on each counter, choose Counter PC and enter the new address.
• Some antivirus programs have their own firewall. If the browser test fails with Windows set to Private, allow incoming TCP port 8321 on the main PC in that program.
• Only the main PC is activated. Counter PCs work under its licence and are not activated separately.
• Every cashier needs a team member account, and your plan limits how many team members you can add.
• Each counter updates its own app when it can reach the internet. It holds no data, so it does not wait for a quiet moment.

Common questions

Can counters keep billing when the internet is down?

Yes. Counters talk to the main PC over the shop network, not the internet. What stops them is the main PC or the router being off.

The main PC is on but the counter cannot reach it. What should I check?

Check that the main PC's network is Private, that its IPv4 Address has not changed, and that the counter box was ticked when it was installed. The browser test at http://<main PC address>:8321 tells you whether the problem is the network or MediPOS.

Do I need to back up counter PCs?

No. Everything is on the main PC, which backs itself up every day.

Can a laptop on Wi-Fi be a counter?

Yes, if it runs 64-bit Windows 10 or 11 and joins the same router as the main PC.

Related guides

• Installing MediPOS Offline
• Setting up thermal receipt printers
• Team members, roles and permissions
• Backups and updates