4-2 Function Mode To connect the ModBus, connect each Inverter in parallel as below. Connect a termination resistor separately to avoid signal reflection, since this 3G3JX does not incorporate it. Choose a termination resistor according to the impedance characteristics of the cable to be used. 4 External controller (master) Functions „ ModBus Setting Switching from the External OPE to ModuBus 1. Set the parameters using the Digital Operator in accordance with your communication environ- ment. 2. Shut off the power. 3. Open the connector cover. 4. Insert the communication cable connected to the ModBus bus line. 5. Set the 485/OPE communications selector to "485". 6.
Turn on the power and start ModBus communications. Switching from ModuBus to the External OPE 1. Remove the ModBus communication line from the RJ45 connector of the Inverter while the Inverter is stopped. Wait 30 seconds to operate the Digital Operator. 2. Set parameter C070 to "02" (OPE) using the Digital Operator and save it. 3. Shut off the power. 4. Set the 485/OPE selector S7 to "OPE" and connect the external OPE to the RJ45 connector. 5. Turn on the power and start external OPE communications. Operating area of the Inverter OPE → MODBUS Enlarged view of the operating area MODBUS → OPE Enlarged view of the operating area S7 S7 485 S8 485 S8 OPE ON OPE ON OFF OFF Note:
Be sure to set parameter C070 in advance. Communication protocol will not be changed merely by switching S7. 4-78 Termination resistor 8k8k8k8 SP SN ModBus network Termination resistor 8k8k8k8 8k8k8k8