Missing Terminating Resistors

If only one terminating resistor is missing from a J1939 data backbone it will likely function problem free, though if you scoped the waveform it could be noticed due to longer capacitive discharge times and increased signal reflections. However, if both terminating resistors are missing, no communication can take place. When this happens, there is an increase in the length of time required for each signal pulse pumped down the bus to neutralize, and the resulting signal reflections scramble the data bus so no transactions are possible.

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