20-750sc-8U

Utilizing the 20-750sc-8U option card within the Allen Bradley PowerFlex 753 series enhances the system's capabilities for managing diverse analog signals. This card includes eight input channels, where pairs may be designated for RTD applications, optimizing its versatility across different measurement contexts. It accepts a wide range of signals, including voltage measurements of ±50 mV, ±100 mV, 0–5 V, 0–10 V, and ±10 V, accompanying current inputs of both 0–20 mA and 4–20 mA.

Resistance measurements can be conducted across multiple ranges, notably from 0–20 Ω (only for even channels) to higher resistances, which include 0–150 Ω, 0–500 Ω, 0–1 kΩ, and 0–3 kΩ. This card is compatible with various RTD types, such as platinum, nickel, copper, and nickel-iron, ensuring broad applicability.

Designed for precision, the 20-750sc-8U option card provides a resolution of 20 bits, which is vital for maintaining accuracy in measuring dynamic signals. The card supports different filter rates, which enhance the stability and reliability of the input signal by filtering out noise at specified frequencies—4, 17, 60, 240, and 470 Hz.

Typical accuracy standards are strongly adhered to, including ±6 mV for voltage readings and ±50 µA for current measurements, along with corresponding accuracy specifications for resistance and RTD inputs. Noise rejection is robust, with a common-mode rejection ratio (CMRR) of 84 dB at 50/60 Hz, contributing to reliable data capture.

Input impedance measurements show a high value of 10 MΩ for voltage and 249 Ω for current inputs, supporting compatibility with a vast array of sensors. The isolation spec offers 250 VAC to the chassis while noting that there is no isolation between channels. The power requirements for this card indicate a draw of approximately 250 mA from a 12 VDC bus, consuming less than 3 watts of power overall. Connections are facilitated via a 64-pin card edge and a 24-pin terminal block, ensuring a straightforward integration process into compatible systems.