YASKAWA G7

37
RS-422/RS-485 Communication
The following is a quick reference guide for troubleshooting RS-422/RS-485 communication to the G7 drive. Make a copy of the following
pages and check-off each item as it is completed. For detailed information on the RS-422/RS-485 standard please refer to EIA RS-422-A or later
revision. For information on the G7 drive RS-422/RS-485 interface, refer to previous sections of this manual.
1: For RS-422/RS-485 communications.
1.1: Verify that the correct cable is used to connect the controller to the G7 drive.
1.2: Verify that the controller is set for RS-422 or RS-485 communications and that the communications cable is connected
to the correct communications port.
1.3: Record the controller communication parameters.
1.4: Verify that the polarity of the signal wires is correct (+ to + and - to -).
Baud Rate
Parity Data Bits Stop Bits 1
1.5: Record the G7 drive communication parameters (H5-01, H5-02, H5-03, H5-07).
Baud Rate
Parity Data Bits Stop Bits 1
1.6: Verify that the communication parameters match.
1.7: For RS-485 2-wire networks only, verify that G7 drive parameter H5-07 (RTS) is set to 1 (Enable).
1.8: Verify that G7 drive parameter H5-01 (Node Address) is set to the correct, unique, hexadecimal value and that it
matches the node address required by the controller.
2: Check the controller RS-422/RS-485 wiring requirements.
2.1: The controller transmit terminals are connected to the G7 drive receive terminals and the receive terminals connected to
the G7 drive transmit terminals.
2.2: The transmit and receive connection polarities are correct.
2.3: The controller either asserts RTS when transmitting or utilizes send detect circuitry.
2.4: The network is terminated only at the beginning and end of each network segment.
2.5: There are no more than 31 devices on any network segment, including the controller and repeater.
3: Verify that the G7 drive passes the self-test as described in the following section.