EZSeries TextPLC has 2 in-built serial communication ports for PLC that are standard on all models:

Port 1 is an RS-232 port used for programming the PLC and as well as Text panel..

Port 2 is an RS-422/RS-485 port which supports Modbus RTU protocol or ASCII protocol. PLC can act as Modbus slave as well as Modbus master. If you want to extend the Input/Output capability of the PLC, you can do it through Modbus Master/Slave communication via RS-485/RS-422. This RS-485/RS-422 can be used for networking multiple EZPLC, barcode scanners, power meters, temperature scanner which supports modbus RTU or ASCII.

Multiple EZ Marquees can be communicated with port 2 i.e. RS-485/RS-422 via ASCII.

Ethernet is an optional port in the PLC which can be used for communicating with EZ Marquee via Ethernet TCP/IP. This Ethernet port supports Modbus TCP/IP which can be used to extend Input/Outputs. It can also be used for communicating HMI/SCADA and other devices which support Modbus TCP/IP. This optional card is available at an incredible price $ 99.	Modbus TCP/IP Option
EZSeries TextPLC has an optional Profibus slave card for the PLC, this is an add-on option card which allows 244 byte of data exchange b/w Profibus Master and PLC. Profibus master may be a PLC or an HMI or any other device, optional Profibus Slave card is available for $ 129.	Profibus Plug-in option card
To reduce hard wiring and to add device level diagnostics, EZSeries TextPLC has an optional DeviceNet slave card. This add-on option card allows 256 bytes of data exchange between DeviceNet master and PLC. DeviceNet master can be other PLC or a HMI/SCADA or any device. The DeviceNet card is available for $79.	DeviceNet Plug-in option card

As you can see above, EZSeries TextPLC has communication capabilities which are not even found in some of high end PLC's costing several times.