UART DTR, DCD, DSR - HL Series

IoT Modules Legacy HL Series
1

Do we have to use the UART DTR, DCD, and DSR signals when connecting an HL Series module to our host processor?

2

I saw in the product technical specification of HL8548, those pins are supported.

3

Hi sjacobsen，

You can use the 4-wire UART without DTR, DCD, and DSR, RI.
Please refer to product technical specification about the connection.
No impact with the FW upgrade via the 4-wire UART.