It is not possible to communicate via the USB system bus adapter if the LED is on
Question:
What may be the cause for a communication problem of the USB system bus adapter if despite the USB communication path selected and although the LED at the EMF 2177IB is on it is not possible to establish a communication?
Answer:
It is possible to operate several USB system bus adapters simultaneously at one PC. In this case the USB system bus adapters are to be connected are assigned by means of the device address. This is done under the 'Settings' register of the system bus configuration tool.
If there is a communication problem with the USB system bus adapter connected in case of which the red LED is on this may indicate that the device address has been assigned incorrectly.
In this case the following device state is indicated under the 'Common' register during the diagnostics process: An error occurred during initialization of the communication device. (A117)
The yellow 'warning triangle' indicated in front of the hardware (EMF2177IB) selected signals that this component has not been recognised.
The error can be remedied by assigning the device clearly to a specific device address. Since the module address saved cannot be read out it is required that the module is parameterised by means of a device address which has not been used before (under 'Settings=>Device address'). However, the parameters can only be set if one single USB system bus adapter is connected only.
