CANH/L Diff. V (D)
CANH/L differential shows you the difference between
CANH and CANL for dominant bits:
Display
What it means
Current CANH/L
dominant voltage
differential is 1.67V.
Minimum CANH/L
dominant voltage
differential since the
NetMeter was
plugged in or reset is
1.00V.
Maximum CANH/L
dominant voltage
differential since
NetMeter was
plugged in or reset is
1.76V.
x1
x2
CANH/L diff. V(D) = CANHV(D) - CANLV(D)
Switch
10
12
8
V
250
MAX
V
250
8
20
V
250
MIN
Dominant differential bus
voltage can not be
measured because there
is no bus activity.
Why is this measurement important?
See the description of "recessive" on page 18.
The dominant differential voltage is usually around 2V. A
lesser differential voltage may be mis-interpreted by a
transceiver as a recessive bit - causing bus errors.
At the beginning of each frame it is possible for several
nodes to transmit simultaneously resulting in a dominant
differential >3V. NetMeter accurately measures dominant
voltage by sampling only when one node is transmitting.
A measured dominant differential (single node
transmitting) larger than 3V is a clear indication of a
network problem.
Why is this measurement important?
