Net-H/L Differential V Recessive (Switch Position 7); Importance Of Net-H/L Differential V Recessive Measurement - Maretron N2KMeter User Manual

13 NET-H/L Differential V Recessive (Switch Position 7)

NET-H/L differential (Recessive) shows you the difference between NET-H and NET-L for
recessive bits:
NET-H/L diff. V(R) = NET-HV(R) - NET-LV(R)
Display

13.1 Importance of NET-H/L Differential V Recessive Measurement

Data bits (0's and 1's) are transmitted as differences in voltage between the NET-H and NET-L
wires. The differential voltage measurements are essentially a measurement of "signal quality".
The recessive differential voltage is ideally zero, but typically is plus or minus a few millivolts.
A recessive differential voltage that is not sufficiently close to zero may be misinterpreted by a
transceiver as a dominant bit - resulting in communication errors.
Thresholds
Diff R Voltage High Fault
Diff R Voltage Low Fault
Revision 1.3
What it means
Current NET-H/L recessive voltage
differential is 0.09V.
Minimum NET-H/L recessive voltage
differential since the N2KMeter was
plugged in or reset is 0.08V.
Maximum NET-H/L recessive voltage
differential since N2KMeter was
plugged in or reset is 0.09V.
Recessive differential bus voltage
can not be measured because the
bus is stuck dominant.
0.08V
-0.18V
Page 19