Register description
The registers can be read or written via the register communication. They are used for the parameterization of the terminal.
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 R4: reserved
- R5: Raw DAC value (Y_dac)
The 12-bit value transferred to the D/A converter is called raw DAC value. It is calculated from the process data via the manufacturer and user scaling.
- R6 to R7: reserved
R8 to R15: Registers in the internal ROM of the terminal
The type and system parameters are hard programmed by the manufacturer, and the user can read them but cannot change them.
- R8: Terminal type
The terminal type in register R8 is needed to identify the terminal.
- R9: Software version (X.y)
The software version can be read as a string of ASCII characters.
- R10: Data length
R10 contains the number of multiplexed shift registers and their length in bits.
The Bus Coupler sees this structure.
- R11: Signal channels
Related to R10, this contains the number of channels that are logically present. Thus for example a shift register that is physically present can perfectly well consist of several signal channels.
- R12: Minimum data length
The particular byte contains the minimum data length for a channel that is to be transferred. If the MSB is set, the control and status byte is not necessarily required for the terminal function and is not transferred to the control, if the Bus Coupler is configured accordingly.
- R13: Data type register
Data type register | Meaning |
|---|---|
0x00 | Terminal with no valid data type |
0x01 | Byte array |
0x02 | Structure 1 byte n bytes |
0x03 | Word array |
0x04 | Structure 1 byte n words |
0x05 | Double word array |
0x06 | Structure 1 byte n double words |
0x07 | Structure 1 byte 1 double word |
0x08 | Structure 1 byte 1 double word |
0x11 | Byte array with variable logical channel length |
0x12 | Structure 1 byte n bytes with variable logical channel length (e.g. 60xx) |
0x13 | Word array with variable logical channel length |
0x14 | Structure 1 byte n words with variable logical channel length |
0x15 | Double word array with variable logical channel length |
0x16 | Structure 1 byte n double words with variable logical channel length |
- R14: reserved
- R15: Alignment bits (RAM)
The alignment bits are used to place the analog terminal in the Bus Coupler on a byte boundary.
R16 to R30: Manufacturer parameter area (SEEROM)
The manufacturer parameters are specific for each type of terminal. They are programmed by the manufacturer, but can also be modified by the controller. The manufacturer parameters are stored in a serial EEPROM in the terminal, and are retained in the event of voltage drop-out.
These registers can only be altered after a code word has been set in R31.
- R17: Hardware compensation - offset (B_a)
This register is used for hardware offset compensation (8-bit digital potentiometer) of the terminal. The register is transferred to the hardware after each processor reset or with each write access to R17. Note that the transferred offset does not correspond to the DAC values. - High byte: reserved
- Low byte: Offset value (0 to 255)
- R18: Hardware compensation - gain (A_a)
This register is used for hardware gain compensation (8-bit digital potentiometer) of the terminal. The register is transferred to the hardware after each processor reset or with each write access to R17. - High byte: reserved
- Low byte: Gain value (0 to 255)
- R19: Manufacturer scaling - offset (B_h)
16 bit signed integer [0x0000]
This register contains the offset of the manufacturer straight-line equation (equation 1.1). The straight-line equation is enabled via register R32.
- R21: Manufacturer's switch-on value
[0 V], 12 bit signed integer in X [0x0000]
The manufacturer switch-on value is applied to the terminal output after a system reset or a watchdog timer overflow (terminal has not received any process data for 100 ms).
The manufacturer switch-on value is enabled via register R32.
R31 to R47: User parameter area (SEEROM)
The user parameters are specific for each type of terminal. They can be modified by the programmer. The user parameters are stored in a serial EEPROM in the terminal, and are retained in the event of voltage drop-out. The user area is write-protected by a code word.
 | • R31: Code word register in RAM The code word 0x1235 must be entered here so that parameters in the user area can be modified. If any other value is entered into this register, the write-protection is active. When write protection is not active, the code word is returned when the register is read. If the write protection is active, the register contains a zero value. |
- R32: Feature register
[0x0006]
This register specifies the operation modes of the terminal. Thus, for instance, a user-specific scaling can be enabled for the analog I/Os.
Feature bit no. |
| Description of the operation mode |
|---|---|---|
Bit 0 | 1 | User scaling (R33, R34) active [0] |
Bit 1 | 1 | Manufacturer scaling (R19, R20) active [1] |
Bit 2 | 1 | Watchdog timer active [1] |
Bit 3 | 1 | Sign / amount representation [0] |
Bits 4 to 7 | - | Reserved, don't change |
Bit 8 | 0/1 | 0bin: Manufacturer switch-on value [0] |
Bits 9 to 15 | - | Reserved, don't change |
- R35: User switch-on value
16 bit signed integer [0x0000]
If the user switch-on value is enabled in register R32, this value is applied to the terminal output after a system reset or a watchdog timer overflow (terminal has not received any process data for 100 ms).