Cable Termination; Shielding And Grounding - Bosch Rexroth CIMS Mk IV Instruction Manual

4.2.2. C
ABLE TERMINATION
The proper termination of the cable is very important. If the cable is not terminated with its
characteristic impedance, distorted waveforms will result. Normally using 120 resistors for cable
termination is adequate, as shown in Figure 15. Note that the diagnostic Modbus output already
has a 120 resistor integrated, so an additional resistor at the receiver side is not necessary.
4.2.3. S
HIELDING AND
It is necessary to connect the cable shields to a proper ground point to discharge the cable shield
from radiated EMI. It is recommended to connect the cable shield to ground according the
connection diagram as depicted in Figure 15. If a grounding system is available, it ensures the
CIMS and the customer equipment are on the same potential, so the cable shield can be
connected at both sides, giving the best EMI protection. If a grounding system is not available, the
shield may only be connected to ground at the customer/receiver side. Also the receiver
electronics must be grounded to prevent unwanted common mode voltages.
The CIMS has both internal and external grounding points, to connect the shield to the CIMS and /
or the CIMS to the cylinder, see Figure 7 and Figure 9. Grounding can be made using an eye cable
tag.
Figure 15: Cable termination and grounding concept.
F 037 300 069 (2013.05.21)
G
ROUNDING
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