MODBUS_REPLY_EXCEPTI(3) Libmodbus Manual MODBUS_REPLY_EXCEPTI(3)NAMEmodbus_reply_exception - send an exception reponse
SYNOPSIS
*int modbus_reply_exception(modbus_t *ctx, const uint8_t *req, unsigned
int exception_code);
DESCRIPTION
The modbus_reply_exception() function shall send an exception response
based on the exception_code in argument.
The libmodbus provides the following exception codes:
· MODBUS_EXCEPTION_ILLEGAL_FUNCTION (1)
· MODBUS_EXCEPTION_ILLEGAL_DATA_ADDRESS (2)
· MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE (3)
· MODBUS_EXCEPTION_SLAVE_OR_SERVER_FAILURE (4)
· MODBUS_EXCEPTION_ACKNOWLEDGE (5)
· MODBUS_EXCEPTION_SLAVE_OR_SERVER_BUSY (6)
· MODBUS_EXCEPTION_NEGATIVE_ACKNOWLEDGE (7)
· MODBUS_EXCEPTION_MEMORY_PARITY (8)
· MODBUS_EXCEPTION_NOT_DEFINED (9)
· MODBUS_EXCEPTION_GATEWAY_PATH (10)
· MODBUS_EXCEPTION_GATEWAY_TARGET (11)
The initial request req is required to build a valid response.
RETURN VALUE
The modbus_reply_exception() function shall return the length of the
response sent if successful. Otherwise it shall return -1 and set
errno.
ERRORS
EINVAL
The exception code is invalid
SEE ALSOmodbus_reply(3)libmodbus(7)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
libmodbus 3.1.0 10/06/2013 MODBUS_REPLY_EXCEPTI(3)