Search

Scope: Core (OPC-10000-*) All specs

19 result(s) for CRC

OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

4.1 General

uses a MonitoringNumber , a timeout, a set of IDs and a cyclic redundancy check ( CRC )code for the detection of all possible communication errors which can happen in the underlying
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

5.3 Safety measures

Instance of "data integrity assurance" of IEC 61784‑3, based on CRC signature. The SafetyConsumer is specified in such a way that for any communication error according
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

5.5 Requirements for CRC calculation

Requirements for CRC calculation [RQ5.4] Any CRC signature calculation shall start with a preset value of "1". [RQ5.5] Any CRC signature calculation resulting ... shall use the value "1" instead. [RQ5.6] SPDUs with all values (incl. CRC signature) being zero shall be ignored by the receiver ( SafetyConsumer and SafetyProvider ). For Client/Server communication
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

6.2.2.3 Method ReadSafetyData

Table 26 . OutMonitoringNumber MonitoringNumber of the ResponseSPDU , see 7.2.1.9 , 7.2.3.1 , and Figure 11 . OutCRC CRC over the ResponseSPDU , see 7.2.3.6 . OutNonSafetyData "Non-safe data" see 7.2.1.11 . Table
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

6.4.2 Diagnostics messages of the SafetyConsumer

0x14 B, E Yes CRCerrIgn The SafetyConsumer has discarded a message due to a CRC error (data corruption). 0x05 A Yes CRCerrOA The SafetyConsumer has switched to fail-safe substitute ... values due to a CRC error (data corruption). Operator acknowledgment is required. 0x15 B, C Yes CoIDerrIgn The SafetyConsumer has discarded a message due to an incorrect ConsumerID. 0x06
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.1.1 General

details on the RequestSPDUDataType definition. NOTE 1 The RequestSPDU does not contain a CRC signature. Figure 11 - RequestSPDU Figure 12 shows the structure of a ResponseSPDU which originates
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.1.5 ResponseSPDU: SafetyData

comprised of only a single basic OPC UA Variable . For the calculation of the CRC signature, the order in which this data is processed by the calculation is important. SafetyProvider
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.1.10 ResponseSPDU: CRC

ResponseSPDU: CRC [RQ7.7] The ResponseSPDU CRC shall be used to detect data corruption. See 7.2.3.6 on how it is calculated in the SafetyProvider and how it is checked
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.1.11 ResponseSPDU: NonSafetyData

transmit NonSafetyData values (e.g. diagnostic information) together with SafetyData consistently. NonSafetyData is not CRC -protected and can stem from an unsafe source. [RQ7.9] When presented to the safety application
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.2.4 SafetyProvider state diagram

Flags, the SafetyData and the NonSafetyData , as well as the calculated CRC . See 7.2.3.1 Table 31 shows the states of a SafetyProvider instance. The SafetyProvider does not check for correct
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.2.5 SafetyConsumer state diagram

CRCCheck_i Boolean Local variable used to store the result of the CRC check SPDUCheck_i Boolean Local variable used to store the result of the additional SPDU checks SPDU ... ResponseSPDU is characterized by a change in the MNR . S15_CRCCheckSPDU // Check CRC uint32 CRC_calc CRCCheck_i:= (CRC_calc == ResponseSPDU.CRC) // see 7.2.3.6 on how to calculate CRC_calc
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.3.1 Build ResponseSPDU

calculation of the SPDU_ID , see 7.2.3.2 . For the calculation of the CRC
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.3.5 Signature over the SafetyData Structure (SafetyStructureSignature)

orientation using Euler angles. [RQ7.19] SafetyStructureSignature shall be calculated as a 32 bit CRC signature (polynomial: 0xF4ACFB13, see Clause B.1 ) over SafetyStructureIdentifier (encoding: UTF-8), SafetyStructureSignatureVersion and the sequence ... this case. The terminating zero of SafetyStructureIdentifier shall not be considered when calculating the CRC . [RQ7.20] SafetyStructureIdentifier may be visible in the OPC UA Information Model for diagnostic purposes
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

7.2.3.6 Calculation of a CRC signature

Calculation of a CRC signature The SafetyProvider calculates the CRC signature ( ResponseSPDU.CRC ) and sends it to the SafetyConsumer as part of the ResponseSPDU . This enables the SafetyConsumer to check ... ResponseSPDU including the SafetyData , flags , MNR , SafetyConsumerID and SPDU_ID by recalculating the CRC signature (CRC_calc). [RQ7.22] The generator polynomial 0xF4ACFB13 shall be used for the 32-Bit CRC
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

9.3.1 Probabilistic considerations (informative)

multiplied by the so-called conditional residual error probability Pre,cond. For the CRC mechanism used in this document, it holds: Pre,cond ≤ 4,0 × 10-10 This leads ... justified by extensive numerical evaluation of the 32-bit CRC generator polynomial in use (0xF4ACFB13). The results of this evaluation, executed for all relevant data lengths and all relevant values
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

9.3.2 Safety related assumptions (informative)

listed here. Generally: Number of retries in the underlying standard transmission system : No restrictions CRC polynomials used inside the underlying standard transmission system (e.g. Ethernet, TCP, …): No restrictions Message storing
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

9.4 PFH and PFD values of a logical safety communication link

SafetyConsumer . Whenever the SafetyConsumer detects a mismatch of the SafetyConsumerID , SPDU_ID , MNR or CRC , it will only continue operating if the last occurrence of such an error happened more
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

10.3 Index of requirements (informative)

RQ5.3 Process and monitor safety measures in the SCL 5.3 Safety measures RQ5.4 Start CRC calculation with value "1" 5.5 Requirements for CRC calculation RQ5.5 Use CRC result ... instead of "0" 5.5 Requirements for CRC calculation RQ5.6 Ignore all-zero SPDUs 5.5 Requirements for CRC calculation RQ6.1 Singleton SafetyACSet Folder 6.2.2.1 SafetyACSet Object RQ6.2 Objects
OPC-10000-15 – OPC Unified Architecture - Part 15: Safety

B.1 CRC calculation using tables, for the polynomial 0xF4ACFB13

CRC calculation using tables, for the polynomial 0xF4ACFB13 The calculation of a 32-bit CRC signature over an array of N octets with the help of lookup tables, using ... data, see Figure 23 uint32_t result = 1; // seed value for the calculated CRC int16_t i; // index for(i=N-1;i>=0;i--) // process array in reversed