RDREC

Type	Function block
Description	The function block is used to read a data record from a Profinet IO device. The block is executed by REQ = TRUE. The Profinet address ID of the device/slot/subslot from which the data record is read is specified with the ID input. The INDEX input identifies the data record to be read. The maximum number of bytes which shall be read is specified with the MLEN input. If the data record is read successfully, the VALID output indicates that the read data record is stored in the RECORD parameter. If an error occurs during execution of the function block, ERROR is set to TRUE and VALID is set to FALSE. The STATUS output indicates the error code.
Notes	Before calling the function block, an Application Relation (AR) with the communication partner should be completely established. All parameters have to be set. A maximum of 32 instances of the function block is allowed in the PLCnext Engineer project. Function blocks have to be instantiated. The instance name of the function block has to be declared in the 'Variables' table of the POU where the FB is going to be used. The instance name must be unique within the POU.
Parameters	Inputs REQ Data type: BOOL Description: With REQ = TRUE the function block is executed. If no error occurs during execution, the VALID output is set to TRUE and the program execution continues. If an error occurs during execution, ERROR is set to TRUE and VALID is set to FALSE. ID Data type: DWORD Description: Profinet address ID of the device/slot/subslot. The unique Node ID of the Profinet submodule should be connected to the input. PLCnext Engineer automatically assigns a Node ID to each Profinet submodule on insertion of the module. The Node ID is shown in the 'Submodule List' editor of the Profinet submodule node. You can also use the ADDRESS_TO_ID function block to obtain the Node ID. INDEX Data type: INT Description: Identifies the data record to be read. For indexes greater than 0x7FFF, you either have to use negative values due to the INT data type or perform a type conversion for the INDEX value using the WORD_TO_INT function. MLEN Data type: INT Description: Maximum number of bytes which are read from the data record. The variable applied to RECORD must have at least this length, otherwise an error message will be generated. Input/Output RECORD Data type: ANY Description: Provides the data read. The LEN output indicates the number of bytes. A byte array has to be applied to RECORD. Outputs VALID Data type: BOOL Description: Indicates whether an error occurred when executing the function block. 0   Error occurred. 1   No error occurred. The data read are available at the RECORD input/output. BUSY Data type: BOOL Description: Indicates whether the function block is being currently executed. 0   Function currently not executed. 1   Function currently executed. If the service is not acknowledged within 15 seconds, a timeout occurs. During this time BUSY is TRUE. ERROR Data type: BOOL Description: If an error occurs, the ERROR output is set to TRUE. The STATUS output indicates the error code. STATUS Data type: DWORD Description: Error value. Only valid for ERROR = TRUE. See below for a description of the error codes. If BUSY = TRUE, the output contains the value of the last FB call or the value 0. LEN Data type: INT Description: Number of bytes read.
Error codes	Error codes at the STATUS output Note Error codes which are not listed here are Profinet specific. For information on these error codes, refer to the Profinet specification or the Profinet device manual. Error code (hex) Meaning 0x0000 No error occurred. 0xF001 Too many instances used. 0xF002 Error during initialization of the function block. 0xF003 Invalid ID. 0xF004 Invalid HANDLE/ID. 0xF005 Resources conflict. 0xF006 A function block internal task could not be generated. 0xF007 Too many instances used. 0xF008 Invalid type of a parameter. 0xF009 Invalid parameter value. 0xF00A Unallowed parameter. 0xF00B Invalid length specified. 0xF00C ID could not be created (too many IDs). 0xF00D No entry found that matches the specified ID. 0xF00F No further entries found. 0xF010 Entry in use. 0xF011 Alarm acknowledgement could not be done. 0xF012 Error reading the AR parameters (1st time). 0xF013 Negative acknowledgement received for the execution of a Profinet service. 0xF014 Invalid length for parameter LEN/MLEN or/and data record in RECORD input/output too short. 0xF015 The service used to read the data record from the RECORD input/output could not be run. 0xF016 The service used to write the data record from the RECORD input/output could not be run. 0xF017 Service acknowledgement not received. 0xF018 Invalid INDEX used to access the data record in the RECORD input/output of the Profinet IO device, for example, INDEX greater than 0x7FFF. 0xF019 Unknown command code. 0xF01A Error when starting the Application Relation (AR). 0xF01B Error when stopping the Application Relation (AR). 0xF01C Notification of stopped Application Relation (AR) failed. 0xF01D Setting the "Drive BF" flag failed. 0xF01E Error reading the AR parameters (2nd time).