Input Expander
AES-E range input expander are suitable for the protection of machines and plants with up to four guard devices in combination with an AES guard door monitor.
It is possible to monitor more than four guard devices by connecting a number of input expander in tandem. AES-E range input expander can be used to evaluate switching signals from position switches, safety switches, solenoid interlocks or magnetic safety sensors.
Depending on the circuit arrangements, it is possible to secure the guard device up to Control Category 3 to EN ISO 13849-1.
Design and mode of operation:
The design of the input expander is with redundant circuits throughout. At the heart of the unit are two microprocessors. The enabling outputs for connection to an AES range guard door monitor and all inputs of the input expander unit are monitored and evaluated by both microprocessors. The additional five transistor outputs are short-circuit proof and can be used for purposes.
If a guard device is opened, the microprocessors switch off the enabling outputs to the guard door monitor. The guard door monitor thus blocks the enable signal. The enabling outputs of the input expander unit are then only switched on again when all connected components and the internal functions of the input expander unit have been checked. In the course of a switch-on cycle (opening and closing of at least one of the guard devices), there is recognition of all individual faults on the safety switches, the connections and in the safety monitoring module itself which can lead to a dangerous condition. This always results in the enabling paths to the enable signal thus being blocked.
