DT602 GJR2911200R1 Switch module

The NMBA-01 module is connected to the drive using a fibre optic cable link. Consult the drive documentation as to the corresponding terminals inside the drive. The bus cable and the external power supply are connected to terminal block X2 on the NMBA-01.• The SH terminal is internally connected to the NMBA-01 module earth. The SH terminal is normally used for earthing the Modbus cable shield if there is no other station at which the cable shield is directly earthed. • The SHF terminal is internally connected to the NMBA-01 module earth via an RC filter. The SHF terminal is typically used for earthing the Modbus cable shield.The DG terminal is isolated from the NMBA-01 module earth. This terminal is used for connecting the third conductor of the bus cable. The third conductor – Data Ground – offers a common reference or comparison potential to all modules on the bus.

The NMBA-01 module earth

 is connected to the rail onto which the module is mounted. If the rail is fastened to an earthed metallic assembly plate, the module is automatically earthed, and no external earthing wire is needed. If the rail is fastened to a base that is not earthed, the rail must be connected to the nearest earthing terminal. However, the earthing wire should not be connected to the same terminal as the power cable screens. (See page 3-1.) In the NMBA-01 module there are several built-in earthing terminals (see Figure 4-3 and Figure 4-4 ): • The PE terminal is internally connected to the NMBA-01 module earth. Normally, no external wires need to be connected to this terminal.

Earthing the Modbus Cable Shields

 The Modbus cable shield may be directly earthed at one station only. At other stations the cable shield should be earthed via an RC filter. There are two wiring examples in the figures below. The three-wire connection is the preferred one because of its the better noise immunity.This chapter gives information on configuring the Modbus master station and the drive for communication through the NMBA-01 Modbus Adapter Module.