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I have a situation where I am connecting a sensing device to the input of an 1762-IF4 non-isolated input card to a PLC. The output of the device is a voltage output, where the output varies from 1 to 5V based on a corresponding input. The output of the device is faily low impedance (2k ohms). &nbsp;The card input is a fairly high impedance (200k ohms) which is measured at the differential inputs. The offset can reach up to 200mV, but diminishes once the output is above 50% of scale. The offset is still present even when the analog input module is removed from PLC power.<br />
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When the device is powered and not connected to th PLC no offset can be observed. 
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I have a situation where I am connecting a sensing device to the input of an 1762-IF4 non-isolated input card to a PLC. The output of the device is a voltage output, where the output varies from 1 to 5V based on a corresponding input. The output of the device is faily low impedance (2k ohms).  The card input is a fairly high impedance (200k ohms) which is measured at the differential inputs. The offset can reach up to 200mV, but diminishes once the output is above 50% of scale. The offset is still present even when the analog input module is removed from PLC power.

When the device is powered and not connected to th PLC no offset can be observed. 

Connecting a voltage output to a 1762-IF4 (Rockwell Automation PLC) Analog input card generates unexplained offset

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An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints. Examples of properties typical of embedded computers when compared with general-purpose ones are low power consumption, small size, rugged operating ranges, and low per-unit cost. Modern embedded systems are often based on microcontrollers; the processor(s) used may be types ranging from general purpose to those specialised in certain class of computations, or even custom designed for the application at hand. A common standard class of dedicated processors is the digital signal processor (DSP).