Abstract: A printed circuit board has two contact areas on each surface near one end. The board is sandwiched between two halves of a shell to form a plug in such a way that the contact areas are exposed. The contact areas on one surface are nearer the exposed end than the contact areas on the other. The tip and ring conductors of a pair of wires in a test cord are connected, respectively, with the two contact areas which are nearer the exposed end. A keeper spring which is connected to the shield of the jumper cable, the ground potential, insures that the plug will be retained within a jack into which the plug is inserted by engaging a detent. The detent is connected to ground potential. The jack has two long electrical contacts and two short electrical contacts. The long electrical contacts engage the two contact areas which are farther away from the exposed end and the two short electrical contacts engage the nearer contact areas.

Abstract: A connecting block for a digital cross connect system has printed wiring circuit boards to interconnect terminals on the rear surface with jacks and terminals on the front surface. The terminals on the front surface are multipled to jack appearances also on the front surface of the connecting block. The connecting block has a pedestal which sits on a lower crossarm of a frame. The upper surface of the connecting block has a resilient tang which snaps into an upper crossarm of the frame. The tang is depressed with a screw driver or the like to disengage it from the upper crossarm. The connecting block is suspended by the anterior section of the pedestal from a panel located in front of the lower crossarm to expose the terminals on the rear surface. Conductors in cables to and from digital systems are then terminated on the rear terminals.