I had a few power meters connected in a daisy chain. To ensure the comm and wiring is healthy, I used a third party software modscan32 to read a energy data value. Everthing is perfect. Detail of connection is
SlaveId=2![2_1456843084357_error1.jpg](Uploading 100%) ![1_1456843084356_modscan1.jpg](Uploading 100%) ![0_1456843084355_modscan2.jpg](Uploading 100%)
Modbus PointType=Holding Register
Register Address=43060, 4 byte
The return value of 59.9889 was correct.
(refer to photo 1&2 for result of communication test)
Next I transfer the same daisy chain to USB-RS485 convertor and connected to a serial port of MangoES.
I created a datasource and a datapoint. After enable both the created datasource and datapoint, I tried a modbus read data for same energy data value.
However encounter error message
"There is a problem testing the locator
(com.infiniteautomation.mango.io.serialPort.Exception:port/dev/ttyusb0 in use by mango modbus data source Ds_336910)"
I tried out all three port dev/ttyACM99, dev/ttyUSB0, dev/ttyUSB1 but no success.
Has anyone encounter these message before?
What need to configure for the modbus serial properties in order to read the energy data value from the power meter in the MangoES ?
Are there any special requirement for the connection via USB port?
What are the differences between three port ?
Is it possible to do direct wiring termination to the RS485 terminal block provided by MangoES without a convertor?
Any help will be greatly appreciated.![2_1456843109501_error1.jpg](Uploading 100%) ![1_1456843109500_modscan1.jpg](Uploading 100%) ![0_1456843109499_modscan2.jpg](Uploading 100%) ![alt text](image url)