Component description Resistor bank On commercial vehicles, certain items of data are fed to the EDC which are not required for railway oper- ation. An example of such data is a signal from the tachograph (speedometer, tachograph) which is used for con- trolling or limiting the driving speed (see Page 36). Some unused EDC connections must be closed by resistors since the EDC constantly conducts a signal- range check, as described on Page 20.
Interior circuit 2 3 1 5 R1 0.511 kOhm R5 0.511 kOhm R2 1.37 kOhm R6 1.37 kOhm R7 3.08 kOhm R3 3.08 kOhm R8 8.20 kOhm R4 8.20 kOhm 4 6 8 9 7 2 8 4 3 5 7 6 9 1 Redundant cut-out device Safety relay The relay (redundant cut-out device) is a safety-critical component. If certain faults occur in the EDC system the relay interrupts the voltage supply for the control-rod travel operating magnet. The control rod is pulled back to the stop position by a return spring. The safety relay is under current throughout operation. To activate it (e.g. emergency switch-off of the en- gine) the EDC control unit interrupts the current circuit. 13