NODA relies on hardware from many different manufacturers. For the NODA Modbus Gateway, we have decided on equipment from a Lithuanian company called Teltonika.
Please ensure that the status LED in the lower right corner of the front faceplate is green. If the signal strength indicator next to the status LED is low, please mount the device in a location with a better mobile network signal. If the status LED is flashing yellow or red, please refer to the Teltonika manual found at www.teltonika.lt or contact NODA for support.
As long as the slave has support for Modbus TCP and Holding Registers is where the data is stored, then it should work.
However, there are situations when it is unwise for the NODA Modbus Gateway to write to the Modbus TCP slave continuously. For example, when writes will cause wear on an EEPROM flash. In such situations, data can still be read, but data can not (continuously) be written to the slave.