Product Description:

B & R Automation manufactures the X20AI8321, an analog input module in the X20 Fieldbus Input Output Modules series. As an eight-channel differential current interface, the unit digitizes process signals for PLCs, allowing precise monitoring of sensors and transducers in distributed control systems. Its design supports accurate signal acquisition in applications where stable current measurement is required across multiple field devices.

B&R equips the X20AI8321 with 8 differential input channels, each converted by a successive-approximation ADC. The converter provides 12-bit resolution and completes a sample in 1 ms, aligning with fast closed-loop control cycles. A common-mode rejection of 70 dB suppresses line-referenced noise, while galvanic separation rated at 500 VDC for one minute shields the backplane bus from field transients. The module draws only 0.01 W of bus power, which helps limit heat buildup inside the system. Input bandwidth is limited by a 1 kHz analog filter that reduces aliasing before sampling. Converter gain drift of 0.009% per °C, a gain error of 0.08%, and an offset error of 0.03% support accurate span and zero performance without user trimming. The input topology is differential, so ground potential differences between field devices and the rack have less effect on measurement quality.

Channel-to-channel isolation limits interference to -70 dB of crosstalk, supporting multi-sensor installations that require close signal correlation. The analog front end withstands ±50 mA per channel, allowing direct connection to 0–20 mA or ±20 mA transmitters without series shunts. Each least significant bit represents 4.883 µA/LSB, translating the measurable span into 4096 discrete codes for fine trend detection. The module has an IP20 rating, so it is intended for installation behind panel doors where basic touch protection is sufficient.