Analog input module for a programmable logic controller
AssigneeSiemens Aktiengesellschaft
InventorAlbert Naumovic
Life of this patent
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Abstract
An analog input module for a programmable logic controller, wherein the analog input module has a ground potential, and includes a channel output configured at a first electrical potential, a first channel input configured at a second electrical potential where the absolute value of the second electrical potential is less than the absolute value of the first electrical potential and greater than the absolute value of the ground potential. The analog input module also includes a second channel input, and a third channel input, where the ground potential of the analog input module is the ground potential of the channel output, of the first channel input, of the second channel input and of the third channel input.
Claims10
A method for operating an analog input module in a programmable logic controller, the analog input module having a ground potential for a channel output, for a first channel input, for a second channel input and for a third channel input, the method comprising:
- connecting a two-wire measuring transducer to the channel output of the analog input module and to the first channel input of the analog input module;
- connecting a four-wire measuring transducer to the first channel input of the analog input module and to the second channel input of the analog input module;
- connecting at least one further measurement circuit to the second channel input and to the third channel input of the analog input module;
- generating a first electrical potential which is present at the channel output using a transformer device;
- generating a second electrical potential which is present at the first channel input using the transformer device, an absolute value of the second electrical potential being less than an absolute value of the first electrical potential and greater than an absolute value of a ground potential;
- and
- generating a current for performing a functional test of the connected two-wire measuring transducer as a result of a potential difference between the first electrical potential and the second electrical potential.
An analog input module for a programmable logic controller, the analog input module having a ground potential, comprising:
- a channel output at a first electrical potential;
- a first channel input at a second electrical potential, an absolute value of the second electrical potential being less than an absolute value of the first electrical potential and greater than an absolute value of the ground potential;
- a second channel input;
- a third channel input;
- a two-wire measuring transducer operatively coupled to the channel output and the first channel input;
- and
- a four-wire measuring transducer operatively coupled to the first channel input and the second channel input;
- wherein the second and the third channel input are configured for connecting at least one further measurement circuit;
- and
- wherein the ground potential of the analog input module is the ground potential of the channel output, of the first channel input, of the second channel input and of the third channel input.
Dependencies are inferred from the claim text.