Self-signed certificate for ePOS printers¶

ePOS printers are designed to work seamlessly with Point of Sale systems. Once connected, the two devices automatically share information, enabling the direct printing of tickets from the POS system to the ePOS printer.

Note

These Epson ePOS printers are compatible with Odoo:

TM-H6000IV-DT (Receipt printer only)
TM-T70II-DT
TM-T88V-DT
TM-L90-i
TM-T20II-i
TM-T70-i
TM-T82II-i
TM-T83II-i
TM-T88V-i
TM-U220-i
TM-m10
TM-m30
TM-P20 (Wi-Fi® model)
TM-P60II (Receipt: Wi-Fi® model)
TM-P60II (Peeler: Wi-Fi® model)
TM-P80 (Wi-Fi® model)

To work with Odoo, some models that can be used without an IoT box may require the HTTPS protocol to establish a secure connection between the browser and the printer. However, trying to reach the printer’s IP address using HTTPS leads to a warning page on most web browsers. In that case, you can temporarily force the connection, which allows you to reach the page in HTTPS and use the ePOS printer in Odoo as long as the browser window stays open.

Warning

The connection is lost after closing the browser window. Therefore, this method should only be used as a workaround or as a pre-requisite for the following instructions.

Generate, export, and import self-signed certificates¶

For a long-term solution, you must generate a self-signed certificate. Then, export and import it into your browser.

Important

Generating an SSL certificate should only be done once. If you create another certificate, devices using the previous one will lose HTTPS access.

Navigate to the ePOS’ IP address (e.g., https://192.168.1.25) and force the connection by clicking Advanced and Proceed to [IP address] (unsafe).

warning page about the connection privacy on Google Chrome

Warning page on Google Chrome, Windows 10¶

Then, sign in using your printer credentials to access the ePOS printer settings. To sign in, enter epson in the ID field and your printer serial number in the Password field.

Click Certificate List in the Authentication section, and click create to generate a new Self-Signed Certificate. The Common Name should be automatically filled out. If not, fill it in with the printer IP address number. Select the years the certificate will be valid in the Validity Period field, click Create, and Reset or manually restart the printer.

The self-signed certificate is generated. Reload the page and click SSL/TLS in the Security section to ensure Selfsigned Certificate is correctly selected in the Server Certificate section.

The export process is heavily dependent on the OS and the browser. Start by accessing your ePOS printer settings on your web browser by navigating to its IP address (e.g., https://192.168.1.25). Then, force the connection as explained in the Generate a self-signed certificate tab.

If you are using Google Chrome,

click Not secure next to the search bar, and Certificate is not valid;
go to the Details tab and click Export;
add .crt at the end of the file name to ensure it has the correct extension;
select Base64-encoded ASCII, single certificate, at the bottom of the pop-up window;
save, and the certificate is exported.

Warning

Make sure that the certificate ends with the extension .crt. Otherwise, some browsers might not see the file during the import process.

If you are using Mozilla Firefox,

click the lock-shaped icon on the left of the address bar;
go to Connection not secure ‣ More information ‣ Security tab ‣ View certificate;

Connection is not secure button in Mozilla Firefox browser

scroll down to the Miscellaneous section;
click PEM (cert) in the Download section;
save, and the certificate is exported.

The import process is heavily dependent on the OS and the browser.

Windows 10 manages certificates, which means that self-signed certificates must be imported from the certification file rather than the browser. To do so,

open the Windows File Explorer and locate the downloaded certification file;
right-click on the certification file and click Install Certificate;
select where to install the certificate and for whom - either for the Current User or all users (Local Machine). Then, click Next;
on the Certificate Store screen, tick Place all certificates in the following store, click Browse…, and select Trusted Root Certification Authorities;
click Finish, accept the pop-up security window;
restart the computer to make sure that the changes are applied.

To import an SSL certificate into an Android device, first create and export it from a computer. Next, transfer the .crt file to the device using email, Bluetooth, or USB. Once the file is on the device,

open the settings and search for certificate;
click Certificate AC (Install from device storage);
select the certificate file to install it on the device.

Note

The specific steps for installing a certificate may vary depending on the version of Android and the device manufacturer.

Important

If you need to export SSL certificates from an operating system or web browser that has not been mentioned, search for export SSL certificate + the name of your browser or operating system in your preferred search engine.
Similarly, to import SSL certificates from an unmentioned OS or browser, search for import SSL certificate root authority + the name of your browser or operating system in your preferred search engine.

Check if the certificate was imported correctly¶

To confirm your printer’s connection is secure, connect to its IP address using HTTPS. For example, navigate to https://192.168.1.25 in your browser. If the SSL certificate has been applied correctly, you should no longer see a warning page, and the address bar should display a padlock icon, indicating that the connection is secure.