drayton digistat+2RF unit and an SCR unit not communicating?

Hi there,

I have a drayton digistat+2RF unit and an SCR unit.

The batteries in the unit were recently replaced and although appearing to work and transmit,
the SCR unit doesn't appear to be receiving the signal -- even though it is on and the green LED is on.

Could you tell me what I need to do to fix this, or get the two things "talking" again.

Thank you for your help.

Robert