Circuit arrangement for a microprocessor-controlled remote control system

摘要

In the case of microprocessor-controlled remote control systems, the problem always arose of checking the command loop cyclically or before a switching operation. A check can admittedly be carried out using auxiliary relay contacts, but this is not very reliable. The invention makes possible a check of a two-pole command loop with the aid of a subroutine in the microprocessor, which check consists of an additional circuit in the command loop. This is constructed from two single-pole switches, two resistors, one optocoupler and a plurality of diodes. During one check cycle, the two single-pole switches and the relay contacts in the control loop are controlled by the microprocessor, the optocoupler passing on a defect to the microprocessor and the latter blocking the subsequent switching operation.