modbus_receive(3) Manual Page

int modbus_receive(modbus_t *ctx, uint8_t *req);

The modbus_receive() function shall receive an indication request from the socket of the context ctx. This function is used by Modbus slave/server to receive and analyze indication request sent by the masters/clients.

If you need to use another socket or file descriptor than the one defined in the context ctx, see the function modbus_set_socket(3).

The function shall store the indication request in req and return the request length if successful. The returned request length can be zero if the indication request is ignored (eg. a query for another slave in RTU mode). Otherwise it shall return -1 and set errno.

modbus_set_socket(3) modbus_reply(3)

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