BECKHOFF KL5101-0000 - Manual (Page 9)

Terminal configuration
KL5101 7
3.2 Register description
The complex terminals can be adjusted to different operating modes or
functionalities. The " general description of register " describes the
contents of the registers, which are identical for all complex terminals.
The terminal-specific registers are explained in the section following to it.
The access to the internal registers of the terminal is described in the
section " register communication ".
3.2.1 General register description
Complex terminals that possess a processor are capable of bidirectionally
ex-changing data with the higher-level control system. Below, these
terminals are referred to as intelligent bus terminals. They include the
analog inputs (0-10V, -10-10V, 0-20mA, 4-20mA), the analog outputs
(0-10V, -10-10V, 0-20mA, 4-20mA), serial interface terminals (RS485,
RS232, TTY, data transfer terminals), counter terminals, encoder
interfaces, SSI interfaces, PWM terminals and all other parameterizable
terminals.
Internally, all intelligent terminals possess a data structure that is identical
in terms of it's essential characteristics. This data area is organized in
words and embraces 64 memory locations. The essential data and
parameters of the terminal can be read and adjusted by way of the
structure. Function calls with corresponding parameters are also possible.
Each logical channel of an intelligent terminal has such a structure
(therefore, 4-channel analog terminals have 4 register sets.
This structure is broken down into the following areas:
(You will find a list of all registers at the register overview).
Area Address
Process variables 0-7
Type registers 8-15
Manufacturer parameters 16-30
User parameters 31-47
Extended user area 48-63
Process variables
R0 - R7: Registers in the terminal’s internal RAM:
The process variables can be used in additional to the actual process
image and their functions are specific to the terminal.
R0 - R5: These registers have a function that depends on the terminal
type.
R6: Diagnostic register
The diagnostic register may contain additional diagnostic information. In
the case of serial interface terminals, for example, parity errors that have
occurred during data transfer are indicated.
R7: Command register
High-Byte_Write = function parameter
Low-Byte_Write = function number
High-Byte_Read = function result
Low-Byte_Read = function number