Campbell Scientific CR1000KD CR800 and CR850 Measurement and Control Systems - Page 243

Section 7. Installation scan times, two separate scans can be used with logic to jump between them. If a PulseCount() is used in both scans, then a PulseCountReset is used prior to entering each scan. 7.8.16 Program Signatures A program signature is a unique integer calculated from all characters in a given set of code. When a character changes, the signature changes. Incorporating signature data into a the CR800 data set allows system administrators to track program changes and assure data quality. The following program signatures are available. • text signature • binary-runtime signature • executable-code signatures 7.8.16.1 Text Signature The text signature is the most-widely used program signature. This signature is calculated from all text in a program, including blank lines and comments. The program text signature is found in the Status table as ProgSignature. See CRBasic example Program Signatures (p. 243). 7.8.16.2 Binary Runtime Signature The binary runtime signature is calculated only from program code. It does not include comments or blank lines. See CRBasic example Program Signatures (p. 243). 7.8.16.3 Executable Code Signatures Executable code signatures allow signatures to be calculated on discrete sections of executable code. Executable code is code that resides between BeginProg and EndProg instructions. See CRBasic example Program Signatures (p. 243). CRBasic Example 51. Program Signatures 'Program reports the program text signature (ProgSig = Status.ProgSignature), the 'binary run-time signature (RunSig = Status.RunSignature), and calculates two 'executable code segment signatures (ExeSig(1), ExeSig(2)) 'Define Public Variables Public RunSig, ProgSig, ExeSig(2),x,y 'Define Data Table DataTable(Signatures,1,1000) DataInterval(0,1,Day,10) Sample(1,ProgSig,FP2) Sample(1,RunSig,FP2) Sample(2,ExeSig(),FP2) EndTable 'Program BeginProg ExeSig() = Signature 'initialize executable code signature 243