Rs233 make TXD high just using other pins, I don't want to hook up any serial input

[Simon Jones]

I have just purchased this pair
https://www.aliexpress.com/item/1005003 ... 1802W6GwfD

At the LORA transmit end I will have an on/ off switch. Just need to make TXD high just using other pins, I dont want to hook up any serial input.

The send receive units are pre-set up and are handshaking every minute.

Any ideas