Replacement Sounder will not switch off?

I have just replaced my old bell unit on my Logic 4 Alarm with a Elmdene HS500C Sounder. It seemed a simple case of transferring the 4 connections, which were perfectly obvious, to the new sounder.It is from the Logic panel connected SCB (T) to RTN. SCB(A) to H-. From the Bell connections (B-) goes to R- and (D+) goes to H+
But ,the sounder keeps going even when the Tamper switches are actuated with the cover on - Help