As Concerned the Energy analyzer supports RS485 serial communication. As per that connect it into the correct pins of RS232 you can find which pins are used for a and b. Connect it. you can neglect the ground. But I'm not much sure about does it can be connected to a PLC.
For the readings, you can use the i-Bus tool which is available in the abb website
If you need any clarification more than this let me know