Analog Input Scaling on ABB Totalflow
Key Takeaway
How to scale analog inputs on ABB Totalflow — raw-to-EU conversion, 4-20mA scaling, wire break detection, and calibration verification.
Quick Answer
Totalflow analog inputs produce 16-bit raw counts (0-65535). Configure input range (4-20mA) and engineering unit range (e.g., 0-1500 PSI) in PCCU32 for automatic linear scaling. Wire break detection alarms when the input drops below the 4mA live zero threshold.
Scaling Configuration
Set raw input range and EU range in the I/O configuration. Totalflow performs linear interpolation automatically. Scaled values are stored in registers used by flow calculation applications and reported to SCADA.
Wire Break Detection
Configure alarm below 4mA (typically 3.8mA equivalent). Triggers sensor fault alarm mapped to DNP3 for SCADA notification.
Calibration
Use PCCU32 trim functions (trim low at 4mA, trim high at 20mA) with a reference standard to calibrate each analog input channel. Document calibration for regulatory compliance.
For comparison, see SCADAPack analog scaling and Bristol FB300 analog scaling.
Frequently Asked Questions
When the input drops below the live zero threshold (typically 3.8mA), a sensor fault alarm triggers and can be mapped to DNP3 for SCADA notification.
Yes. When a DP input is assigned to an AGA-3 application, square root extraction is applied as part of the orifice flow equation.