Product Description:

The X20AI2636 analog input module is produced by B&R Automation and belongs to the X20 Fieldbus Input Output Modules series. It provides two differential voltage channels that digitize sensor signals and transfer the resulting data to the controller across the backplane bus. This arrangement suits distributed automation stations where analog measurements must be gathered close to the field device while the main control hardware remains elsewhere. Because the channels are differential, the module can read low-level voltage signals with better resistance to external interference than a single-ended input stage.

Its electronics draw only 0.01 W from the system bus, while the internal analog stage requires 1.2 W. Each channel uses a SAR converter with 16-bit resolution, giving fine measurement granularity for process signals. The conversion cycle lasts 40 μs, and oversampling stores 16 values before averaging them to smooth short-term variation. A front-end filter with a cutoff of 10 kHz preserves usable signal bandwidth, while a common-mode rejection ratio of 70 dB helps suppress noise that appears on both input lines. Crosstalk between channels remains below −70 dB, and the 20 MΩ input impedance reduces loading on connected sensors.

Signal separation is provided by an isolation barrier rated at 500 V eff between the field side and the bus, which helps protect the controller from disturbances on field wiring. Absolute accuracy is maintained with a maximum gain error of 0.08%, supporting reliable scaling of measured values in the control program. The measurement front end tolerates input swings up to ±30 V and can safely handle ±50 mA of input current, so the module can withstand abnormal signal conditions without immediate damage. The isolated design also keeps field-side disturbances from coupling directly into the backplane communication path.