The PPC-J1900-156-C has several expansion connectors on the back side – 3 USB 2.0 connectors, 1 USB 3.0 connector, 2 LAN connectors, 2 COM connectors（2 RS232 by default, and 1*10PIN 3.81mm screw terminal connector ( 4 RS232 and 2 RS485 by default)), and 1 HDMI connector.
Please note that a WiFi module does not come with the product by default, but it can be added. Use the menu in the top right corner of the product page to add it if you need it.
A 4G/LTE module can be added to the product, but we do not currently offer it in our shop. We recommend you buy it locally, and install it yourself, as it’s quite easy to add.
The RS485, and RS232 connector is a 16 Pin 3.81mm screw terminal connector.
Contact us for more information.