Troubleshooting | Siemens SG-6048-01 guide

5 Troubleshooting

If you experience communications errors and suspect the Isolated Multi-Drop converter is at fault, perform the actions listed below. Before performing these tests:

1.Verify that your application software is properly set up.

2.Verify that the cables between the components are connected correctly according to the installation instructions.

If transmission through the Isolated Multi-Drop converter fails (one or more of the Tx LEDs fails to blink), perform the following checks in the order given:

1.If some (but not all four) of the Tx LEDs blink simultaneously, the Isolated Multi-Drop converter is faulty and should be replaced.

2.If none of the Tx LEDs flash, perform the following steps in order:

a.Check the power connection and verify that the PWR LED is lit.

b.Verify that the Tx Control switches are set according to the specifications of your application software.

c.Verify that the PC’s serial port is working properly. If it is, try replacing the cable to the converter.

If data errors occur or if there is no response from the field devices (Rx LED fails to flash), perform the following checks in the order given:

1.If correct data is transmitted from a field device but communication errors occur or no Rx LED flashes, check the following:

a.Verify that the field device is receiving power.

b.Verify that the cable from the converter to the field device is correct.

c.Verify that the device’s communications address matches the address assigned by the software for that device.

d.Verify that the device’s data rate matches that of the software.

2.Verify proper operation of the attached field device’s RS-485 communication interface. For more detailed troubleshooting information on field devices, refer to troubleshooting guidelines in Installing the ACCESS System (Manual No. SG-6028).

3.Verify that the Data(+) and Data(-) port of each device is connected to the corresponding ports of the converter.

Siemens Energy & Automation, Inc.