1 Scope
2 Normative references
3 Definitions
4 Design principles
4.1 General design requirements
4.1.1 Analogue/digital interface
4.1.2 Numerical errors
4.1.3 Measuring operation
4.1.4 Special state indication
4.1.5 Digital indication
4.1.6 Digital reading (not applicable to
alarm only apparatus)
4.2 Software
4.3 Hardware
4.4 Data transmission
5 Test of the digital unit
5.1 Verification of functional concept
5.2 Performance test