There is provided a compound of the formula :wherein x is a nitrogen or CRx, Rx is a hydrogen, etc. A second storage system includes a second storage unit to provide storage volumes, a second storage controller, and a second memory to store a second control program to process an inputoutput request received by the second storage system. The device further includes one or more emergency or alarm signal outputs responsive to the insertion of foreign bodies which, when inserted in the passage, pass through the sensing barrier. The first phase mixer is operable to receive the first enable signal and a first delayed enable signal derived from the first enable signal and generate a first signal on the first driver line having a first configurable delay with respect to the first enable signal by mixing the first enable signal and the first delayed enable signal.