NAME

       modbus_set_slave - set slave number in the context

SYNOPSIS

       int modbus_set_slave(modbus_t *ctx, int slave);

DESCRIPTION

       The modbus_set_slave() function shall set the slave number in the libmodbus context.

       The behavior depends of network and the role of the device:

       RTU
           Define the slave ID of the remote device to talk in master mode or set the internal
           slave ID in slave mode. According to the protocol, a Modbus device must only accept
           message holing its slave number or the special broadcast number.

       TCP
           The slave number is only required in TCP if the message must reach a device on a
           serial network. The special value MODBUS_TCP_SLAVE (0xFF) can be used in TCP mode to
           restore the default value.

       The broadcast address is MODBUS_BROADCAST_ADDRESS. This special value must be use when you
       want all Modbus devices of the network receive the request.

RETURN VALUE

       The modbus_set_slave() function shall return 0 if successful. Otherwise it shall return -1
       and set errno to one of the values defined below.

ERRORS

       EINVAL
           The slave number is invalid.

AUTHORS

       The libmodbus documentation was written by Stéphane Raimbault
       <stephane.raimbault@gmail.com[1]>

NOTES

        1. stephane.raimbault@gmail.com
           mailto:stephane.raimbault@gmail.com