The Industrial Raspberry Pi Forum

Hello,

I am experiencing an issue with my Modbus master setup, where it seems to be working but encounters a timeout. I've attached a screenshot for clarity. Additionally, I have included the configuration file below for reference:

I'm unsure what might be causing this timeout problem or how to resolve it. Any insights or suggestions would be greatly appreciated.

Thank you in advance for your help!

```bash
cat /var/www/revpi/pictory/projects/_config.rsc

# removed in and out
{
"GUID": "6327c725-e309-f66d-bc2b-a1ef6848ce08",
"id": "device_ModbusRTUMaster_20180122_1_1_001",
"type": "VIRTUAL",
"productType": "24580",
"position": "64",
"name": "ModbusRTU Master",
"bmk": "ModbusRTU Master",
"inpVariant": 0,
"outVariant": 0,
"comment": "ModbusRTU Master",
"offset": 11,
"mem": {
"0": [
"device_path",
"/dev/ttyRS485",
"256",
"174",
false,
"0194",
"INFO: value modified to adapt base device type",
""
],
"1": [
"baud_rate",
"9600",
"32",
"206",
false,
"0195",
"",
""
],
"2": [
"parity",
"0",
"8",
"210",
false,
"0196",
"",
""
],
"3": [
"data_bits",
"8",
"8",
"211",
false,
"0197",
"",
""
],
"4": [
"stop_bits",
"1",
"8",
"212",
false,
"0198",
"",
""
]
},
"extend": {
"deviceMisc": {
"tbl_A_rowcount": "1",
"ModbusMasterStatus_ModbusRTUMaster_20180122_1_1": "Modbus_Master_Status",
"MasterStatusReset_ModbusRTUMaster_20180122_1_1": "Master_Status_Reset"
},
"data": {
"ActionId_01_ModbusRTUMaster_20180122_1_1": "1",
"SlaveAddress_01_ModbusRTUMaster_20180122_1_1": "1",
"SlaveIP_01_ModbusRTUMaster_20180122_1_1": "",
"SlavePort_01_ModbusRTUMaster_20180122_1_1": "",
"FunctionCode_01_ModbusRTUMaster_20180122_1_1": "3",
"RegisterAddress_01_ModbusRTUMaster_20180122_1_1": "1",
"QuantityOfRegisters_01_ModbusRTUMaster_20180122_1_1": "2",
"ActionInterval_01_ModbusRTUMaster_20180122_1_1": "1000",
"DeviceValue_01_ModbusRTUMaster_20180122_1_1": "Input_Word_1",
"ModbusActionStatus_01_ModbusRTUMaster_20180122_1_1": "Modbus_Action_Status_1",
"ActionStatusReset_01_ModbusRTUMaster_20180122_1_1": "Action_Status_Reset_1"
}
}
}
```

To resolve the Modbus timeout issue:

1. Check Communication Settings: Ensure baud rate, parity, and stop bits match between master and slave.
2. Verify Connections: Check wiring and termination resistors.
3. Inspect Slave Device: Confirm the slave device is correctly addressed and powered.
4. Review Configuration File: Ensure all settings are correct.
5. Use Diagnostic Tools: Utilize Modbus analyzers to monitor communication.

Adjust timeout settings and ensure detailed logging for more insights.