B–4

Connecting the Inverter to ModBus

Appendix B

4.Terminate Network Wiring - The RS-485 wiring must be terminated at each physical end to suppress electrical reflections and help decrease transmission errors. The L2002 communications port does not include a termination resistor. Therefore, you will need to add termination to the inverter if it is at the end of the network wiring. Select termination resistors that match the characteristic impedance of the network cable. The diagram below shows a network with the needed termination resistor at each end.

 

 

 

 

 

 

ModBus

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Network

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

HITACHI

 

 

POWER

 

 

 

HITACHI

 

 

POWER

 

 

 

HITACHI

 

 

POWER

 

 

 

 

 

 

 

 

 

 

 

ALARM

 

 

 

 

 

ALARM

 

 

 

 

 

ALARM

SP SN

 

 

 

5 0.0

Hz

 

 

 

 

 

50.0

Hz

 

 

 

 

 

5 0.0

Hz

 

 

 

 

 

A

 

 

 

 

 

 

 

 

A

 

 

 

 

 

 

 

 

A

 

 

 

 

 

 

 

 

 

 

RUN

 

 

 

 

 

 

 

 

 

 

RUN

 

 

 

 

 

 

 

 

 

 

 

RUN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RUN

STOP PRG

 

 

 

 

 

 

 

 

RUN

STOP PRG

 

 

 

 

 

 

 

 

RUN

 

STOP PRG

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESET

 

 

 

 

 

 

 

 

RESET

 

 

 

 

 

 

 

 

 

RESET

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FUNC.

1 2

STR

 

 

 

FUNC.

1 2

STR

 

 

 

FUNC.

1 2

STR

Host device

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

L2002

 

 

 

L2002

 

 

 

 

L2002

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5.Set Inverter OPE/485 Switch - The inverter serial port accepts a connection to either a remote keypad device or to the network. You will need to set the DIP switch on the inverter to configure the port for ModBus communications. Setting the switch will require removing the front housing cover. Remember to power OFF the inverter before removing the cover or changing the DIP switch setting. Refer to “Front Housing Cover” on page 2–3 for detailed instructions.

Locate the OPE/485 DIP switch as shown in the figure below. Carefully move the switch to the upper position labeled “485” (slide in direction of arrow). Then replace the front housing cover.

SR 485 TM

SK

OPEPRG

At this point the electrical network connection is complete. The next step will show how to configure parameters and settings related to ModBus communications.