1MODBUS_RECEIVE_CONFI(3)        libmodbus Manual        MODBUS_RECEIVE_CONFI(3)
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NAME

6       modbus_receive_confirmation - receive a confirmation request
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SYNOPSIS

9       int modbus_receive_confirmation(modbus_t *ctx, uint8_t *rsp);
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DESCRIPTION

12       The modbus_receive_confirmation() function shall receive a request via
13       the socket of the context ctx. This function must be used for debugging
14       purposes because the received response isn’t checked against the
15       initial request. This function can be used to receive request not
16       handled by the library.
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18       The maximum size of the response depends on the used backend, in RTU
19       the rsp array must be MODBUS_RTU_MAX_ADU_LENGTH bytes and in TCP it
20       must be MODBUS_TCP_MAX_ADU_LENGTH bytes. If you want to write code
21       compatible with both, you can use the constant MODBUS_MAX_ADU_LENGTH
22       (maximum value of all libmodbus backends). Take care to allocate enough
23       memory to store responses to avoid crashes of your server.
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RETURN VALUE

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

32           uint8_t rsp[MODBUS_MAX_ADU_LENGTH];
33           rc = modbus_receive_confirmation(ctx, rsp);
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SEE ALSO

36       modbus_send_raw_request(3)
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AUTHORS

39       The libmodbus documentation was written by Stéphane Raimbault
40       <stephane.raimbault@gmail.com>
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44libmodbus v3.1.7                  07/20/2023           MODBUS_RECEIVE_CONFI(3)
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