Issue
7798C does communicate with a PC with either cable -- CBL082 or CBL072
Product Line
TAC INET
Environment
I/NET Controllers including the 7798C
Cause
Improper Grounding
Resolution
There must be an earth ground connected to pin #3 of the 24 VAC power connector in order for communications to work correctly.
Click on these pictures for a larger example:
Note: Never use the shield as the ground. Grounding is accomplished by connecting a 14–18 AWG (2.081–0.897 mm2) wire from terminal 3 to true ground.