In order to be able to increase safety in elevator systems, a connecting device for connecting a transmission device for transmitting information is provided, wherein the transmission device is attached to a measurement tape for determining the position of a cab in an elevator shaft and wherein the connecting device is designed as a guide bracket for guiding and/or supporting the measurement tape, so that the guide bracket at least partially surrounds the measurement tape, and wherein the guide bracket has at least one opening for reading out the marking unit, and wherein the connecting device has two connection contacts for connecting to one of the communication lines and/or supply lines and an interruption device for interrupting one of the communication lines and/or supply lines, wherein the interruption device is situated in such a way that the interruption occurs between the two connection contacts.