Is it possible to send/recieve on RS485 without flow control. I am working on stm32f4 platform with a MAX3160 multiprotocol transceiver(supports RS232 and RS485). The UART lines form STM32F4 are connected to the MAX3160. When the MAX3160 is configured to RS232 it works fine. But when configured to RS485(only 1 pin toggle on MAX3160, input/output lines are same) i am not able to send/receive data. The devices connected to RS485 are using modbus protocol. I am not using RTS/CTS and have configured NO_FLOWCONTROL on UART. My modbus devices also has just 2 wires A+ and B-.

Could the RS485 data enable or not configuring CTS/RTS causing this issue.

I am not very experienced in hardware. So any pointers will help.