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modbus_reply_exception(3) [debian man page]

MODBUS_REPLY_EXCEPTI(3) 					 Libmodbus Manual					   MODBUS_REPLY_EXCEPTI(3)

NAME

       modbus_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:

       o   MODBUS_EXCEPTION_ILLEGAL_FUNCTION (1)

       o   MODBUS_EXCEPTION_ILLEGAL_DATA_ADDRESS (2)

       o   MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE (3)

       o   MODBUS_EXCEPTION_SLAVE_OR_SERVER_FAILURE (4)

       o   MODBUS_EXCEPTION_ACKNOWLEDGE (5)

       o   MODBUS_EXCEPTION_SLAVE_OR_SERVER_BUSY (6)

       o   MODBUS_EXCEPTION_NEGATIVE_ACKNOWLEDGE (7)

       o   MODBUS_EXCEPTION_MEMORY_PARITY (8)

       o   MODBUS_EXCEPTION_NOT_DEFINED (9)

       o   MODBUS_EXCEPTION_GATEWAY_PATH (10)

       o   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 ALSO

       modbus_reply(3) libmodbus(7)

AUTHORS

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

NOTES

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

libmodbus 3.0.3 						    05/26/2012						   MODBUS_REPLY_EXCEPTI(3)

Check Out this Related Man Page

MODBUS_REPORT_SLAVE_(3) 					 Libmodbus Manual					   MODBUS_REPORT_SLAVE_(3)

NAME

       modbus_report_slave_id - returns a description of the controller

SYNOPSIS

       int modbus_report_slave_id(modbus_t *ctx, uint8_t *dest);

DESCRIPTION

       The modbus_report_slave_id() function shall send a request to the controller to obtain a description of the controller.

       The response stored in dest contains:

       o   the byte count of the response

       o   the slave ID, this unique ID is in reality not unique at all so it's not possible to depend on it to know how the information are
	   packed in the response.

       o   the run indicator status (0x00 = OFF, 0xFF = ON)

       o   additional data specific to each controller. For example, libmodbus returns the version of the library as a string.

RETURN VALUE

       The modbus_report_slave_id() function shall return the number of read data if successful. Otherwise it shall return -1 and set errno.

EXAMPLE

	   uint8_t *tab_bytes;

	   ...

	   rc = modbus_report_slave_id(ctx, tab_bytes);
	   if (rc > 1) {
	       printf("Run Status Indicator: %s
", tab_bytes[1] ? "ON" : "OFF");
	   }

AUTHORS

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

NOTES

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

libmodbus 3.0.3 						    05/26/2012						   MODBUS_REPORT_SLAVE_(3)
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