Process variables
R0 to R7: Registers in the internal RAM of the terminal
The process variables can be used in addition to the actual process image. Their function is specific to the terminal.
R0 to R5: Terminal-specific registers
The function of these registers depend on the respective terminal type (see terminal-specific register description).
- R6: Diagnostic register
The diagnostic register can contain additional diagnostic information. Parity errors, for instance, that occur in serial interface terminals during data transmission are indicated here.
- R7: Command register
High-Byte_Write = function parameter
Low-Byte_Write = function number
High-Byte_Read = function result
Low-Byte_Read = function number