Dear
The logic levels of the outputs Rx and Tx from Arduino Uno are 0-5V. Is it possible Connect to the C1 and C2 (Com1) of the Cr310 with the Rx and Tx of Arduino directly?.
C1----Rx
C2----Tx
Alternatively, you could possibly connect C2/C2 to another set of C ports and transmit and receive between the C ports to test.
There is a possibility that you could connect C2/C2 to another group of C ports and then test the ability to send and receive data between the C ports. https://www.campbellsci.co.uk/forumcluster rush