Toshiba VF-A7 Instruction Manual

Also see for TOSVERT VF-A7: Instruction manual Instruction manual Instruction manual Instruction manual Function manual

154. GroundingGrounding is of particular importance for reliable, stable operation. Communicationsystem characteristics may vary from system to system, depending on the systemenvironment and grounding method used. The ETH-100 interface is provided with aìGNDî screw terminal on the bottom of the unit. This ìGNDî terminal constitutes aneffective ìchassis groundî, and is directly connected to the metallic housing of theshielded RJ45 Ethernet network connector and to the appropriate locations on itsintegrated isolation magnetics.This chassis ground plane is physically separate from the ETH-100ís control logicground plane, which is directly referenced to the CC (control common) terminal onthe connected drives. Switch SW1 #2 on the ETH-100 unit, however, provides amethod to selectively connect these 2 ground planes together.When switch SW1 #2 is ON (switch in the ìdownî position when looking at the bottomof the ETH-100 unit end-on), the ETH-100ís control logic ground plane and chassisground plane are connected together. In this configuration, no external GND wireshould be connected to the unitís GND terminal. In this case, the chassis groundplane is directly connected to the drivesí CC reference, and Toshiba typicallyrecommends that the CC reference of the drives not be connected to earth ground.Refer to your driveís instruction manual for specific information about the CC terminaland ground connections.In some high-noise environments or under unusual wiring conditions, it may bepossible to obtain improved Ethernet communication characteristics by referencingthe ETH-100ís ìchassis groundî to a localized earth ground. In these cases, placeswitch SW1 #2 in the OFF (up) position and connect the GND screw terminal to anappropriate ground connection.Please be sure to consider the following general points for making proper groundconnections:Grounding method checkpoints1. Make all ground connections such that no ground current flows through the caseor heatsink of a connected drive.2. Do not connect the ETH-100ís GND terminal to a power ground or any otherpotential noise-producing ground connection (such as a driveís ìEî terminal).3. Do not make connections to unstable grounds (paint-coated screw heads,grounds that are subjected to inductive noise, etc.)