Solution:

Termination resistors are factory installed to allow for impedance matching. A resistor can be enabled by utilizing jumper 9. Basically, the PCL-841 and default ADAM-5000/CAN were terminal. So you have to remove jumper 9 when you have more then one ADAM-5000/CAN in a project. For example, you have 3 ADAM-5000/CAN for your project. You have to remove the jumper 9 of ADAM-5000/CAN #1 and ADAM-5000/CAN #2. PCL-841 <---> ADAM-5000/CAN #1 (remove JP9) <---> ADAM-5000/CAN #2 (remove JP9) <---> ADAM-5000/CAN #3.