Low cost multi-range input circuit for industrial analog input modules

An input circuit for an analog input module, said input circuit comprising:

• a voltage input terminal;
• a current input terminal;
• a common terminal;
• and
• an output terminal;
• said input circuit configured to accept a voltage input between said voltage input terminal and said common terminal, accept a current input between said current input terminal and said common terminal, and provide an output voltage at said output terminal dependent upon either said voltage input or said current input without switching therebetween.

An analog input module for a controller, said analog input module comprising:

• means for processing signals from external means for sensing;
• means for converting said signals from analog to digital form;
• and
• an output of said means for processing signals connected to said means for converting said signals from analog to digital form;
• wherein said means for processing signals is provided with voltage input means, current input means, and signal return means;
• said means for processing signals includes means for accepting a voltage input between said voltage input means and said signal return means, means for accepting a current input between said current input means and said signal return means, and means for providing an output voltage at said output means dependent upon either said voltage input or said current input without switching therebetween.

An apparatus for processing signals from external sensors for an analog input module, said apparatus comprising:

• voltage input means;
• current input means;
• signal return means;
• output means;
• means for accepting a voltage input between said voltage input means and said signal return means;
• means for accepting a current input between said current input means and said signal return means;
• and
• means for providing an output voltage at said output means dependent upon either said voltage input or said current input without switching therebetween.