Trying to setup DD2500 (Serial)

I have just purchased a DD2500 which I am trying to setup. 

I have followed the instructions as per https://www.slac.stanford.edu/grp/cd/soft/unix/documents/Data-Domain-DD2500-Installation-and-Setup-Guide.pdf but I am unable to connect to the device via the serial port.

I have tried putty and a couple of alternatives to no avail. 

Any help on how to proceed would be greatly appericated.

Thanks