why support uart_hw_flowcontrol_t is not supported (IDFGH-12260)

[yel-best]

Hi,

According to my understanding, it seems that esp-modbus does not support flow control? Hardware flow control is not supported, and software flow control is not known to be supported.

What is the reason?

[alisitsyn]

Hi @yel-best,

There are similar issues for this, one is answered here. This stack supports the standard communication options for RTU and ASCII as per Modbus spec:

RTU: 1 start bit 8 data bits, least significant bit sent first 1 bit for even/odd parity; no bit for no parity 1 stop bit if parity is used; 2 bits if no parity

ASCII: 1 start bit 7 data bits, least significant bit sent first 1 bit for even/odd parity; no bit for no parity 1 stop bit if parity is used; 2 bits if no parity

The API will not be changed here. However, If you need to use some custom serial options in your application you are free to do this. This can be accomplished by overriding the serial settings after call to mbc_master_setup(). See the related link above.

[yel-best]

Hi @yel-best,

There are similar issues for this, one is answered here. This stack supports the standard communication options for RTU and ASCII as per Modbus spec:

RTU: 1 start bit 8 data bits, least significant bit sent first 1 bit for even/odd parity; no bit for no parity 1 stop bit if parity is used; 2 bits if no parity

ASCII: 1 start bit 7 data bits, least significant bit sent first 1 bit for even/odd parity; no bit for no parity 1 stop bit if parity is used; 2 bits if no parity

The API will not be changed here. However, If you need to use some custom serial options in your application you are free to do this. This can be accomplished by overriding the serial settings after call to mbc_master_setup(). See the related link above.

oh, ok, thanks for your advice 😄

[alisitsyn]

@yel-best, the issue is closed.

[alisitsyn]

Update: the documentation will be updated a per your issue as below: