Hi,
I have been asked to convert part of an existing system which uses mechanical inputs in the form of switches from a remote location. This remote location is to be converted to a PLC (Siemens S7), but for the time being keep the original infrastructure of the main panel.
Looking at the problem, the mechanical inputs to the system would now become digital outputs of the PLC back to the original board.
There is a common control voltage and the rest of the contacts are either NO or NC.
Because of the fact that the digital output card of the PLC supplies a voltage, is there any simple way to convert these to volt free outputs? (Or alternatively, retain the state of these controls as input?)
Regards,
henno2000
I have been asked to convert part of an existing system which uses mechanical inputs in the form of switches from a remote location. This remote location is to be converted to a PLC (Siemens S7), but for the time being keep the original infrastructure of the main panel.
Looking at the problem, the mechanical inputs to the system would now become digital outputs of the PLC back to the original board.
There is a common control voltage and the rest of the contacts are either NO or NC.
Because of the fact that the digital output card of the PLC supplies a voltage, is there any simple way to convert these to volt free outputs? (Or alternatively, retain the state of these controls as input?)
Regards,
henno2000