The CMM311 is a serial communications module for a 90-30 PLC. There is no user program in it. All setup is done in hardware configuration of the PLC.
The module has two serial ports. Each port can be configured for protocol and port settings. It supports three protocols (slave only), SNP, CCM, and Modbus.
The cable required depends on what you want to connect to it. It's typical use is for an HMI panel.