Interbus Distributed I/O Controller IBS CAB

I have a customer whos machine uses a Siemens Simatic S5-135U. in the main rack is fitted a Interbus Distributed I/O Master called a IBS S5 DAB Version "A", hardware version 3.2B

The Interbus master card was sold by Phoenix Contact in the UK.

I am seeking the software to save the parameters to disk. The earliest version of the software in our possession is IBS Sysswt E version 2.50 but it appears that we require an even earlier version to successfully copy the parameters.

Any information or copy of the appropriate software would be appreciated !