Is there any other way to check other than using a max232 cable?

There sure is.

For 250's log into the web interface (192.168.100.1) and check the following details:

Boot Code Version : 3.1.6d
Software Version : 2.94.1014
Hardware Version : 1.19

Anything lower than this has the 'p' option, I believe 255's are the same

Excellent, thanks!