<td style="vertical-align:middle;">Swapping RS485 A and B lines (or RS232 Tx and Rx) of the external device and also not connecting ground together - May cause irreparable damage.</td>
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<td style="vertical-align:middle;">Swapping RS485 A and B lines (or RS232 Tx and Rx) of the external device and also not connecting common ground first - May cause irreparable damage.</td>