Exchange 2013 RTM -> Get-ServerHealth -HealthSet not working

Hi

1)What is means by rtm release? Is this the beta version of exchange servers.

2) The -HealthSet parameter of Get-ServerHealth is not working in exchange 2013 rtm version.But in all documention  it is said to be supported from 2013. Can anyone say from which cu(cumulation update) of 2013 the healthset parameter is supported.?

Thanks & Regards,

Bharani