Reading values of Cluster

I am trying to read the values of a BITMAP8 cluster as shown in the code below. However I don’t know how to do this. I tried using “event.value” but it only returns the 1st bit of the bitmap. How can program this to read any value (any bit) of the BITMAP8? I’d really appreciate any help.

    if (descMap.clusterInt == CLUSTER_POWER && descMap.attrInt == MAINS_ALARM_MASK) { = "battery"
        event.value = descMap.value
        log.debug "Event Value: $event.value"