t1 Fall+Off Time (RFID)

Menu Path: Trace > Data > Demod > Summary NFC

t1 Fall+Off Time displays the average, maximum, and minimum fall + off times for pulses within the selected burst (Burst Index). A pulse's t1 Fall+Off Time is the time from the upper threshold on the falling edge of the pulse to the lower threshold on the rising edge of the pulse.

The upper and lower thresholds for pulses can be set on the Advanced tab of the RFID Demod Properties using the ASK Upper and ASK Lower parameters.

To set the t1 value to be measured according to a particular standard, configure the demodulator by clicking MeasSetup > RFID Demod Properties > Format tab > Preset to Standard... and selecting the desired standard and bit rate.

t1 Fall+Off Time is calculated from the data displayed in the Demod Meas Time trace. The average, maximum, and minimum values are calculated for each measurement.

For compatibility with the ISO 14443 Type A standard, the ASK Lower Threshold should be 5% when analyzing ISO 14443 Type A signals at bit rates of 106 kbps and 10% when analyzing ISO 14443 Type A signals at bit rates of 212 kbps or higher. The thresholds can be set by clicking Preset to Standard and selecting the ISO 14443 Type A standard and the desired bit rate.

The previous ISO 14443A t1 value for bit rates higher than 106 kbps is still calculated and displayed on the Summary NFC table as t1 Old.