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 R5: Terminal-specific registers

The function of these registers depend on the respective terminal type (see terminal-specific register description).

R0: Raw ADC value X_R

This register contains the raw ADC value.

R1: Raw ADC value of the line resistance between +R1 - RL1 or +R2 - RL2

R2 to R5: Reserved

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.

R6: Diagnostic register

High byte: not used
Low byte: Status byte

R7: Command register

High-Byte_Write = function parameter
Low-Byte_Write = function number
High-Byte_Read = function result
Low-Byte_Read = function number

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

Value

Data type

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 word

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)

16-bit signed integer
This register is used for offset compensation of the terminal (Eq. 1.1).
Register value approx. 0xEDXX

R18: Hardware compensation – gain (A_a)

16 bits * 16-5 (approx. 0,01907 Ω/digit)
This register is used for gain compensation of the terminal (Eq. 1.1).
Register value approx. 0x27XX

R19: Manufacturer scaling – offset (B_h)

16-bit signed integer [0x0000]
This register contains the offset of the manufacturer's straight-line equation (1.5). The linear equation is enabled via register R32.

R20: Manufacturer scaling – gain (A_h)

16 bits signed integer *2-8 [0x00A0]
This register contains the scaling factor of the manufacturer's straight-line equation (1.5). The linear equation is enabled via register R32.

R21: Additional offset register for two-wire connection

The value of register 1 at short circuit +R1-RL1 or +R2-RL2 [approx. 0x01AX]

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 read-only 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

This register specifies the operation modes of the terminal. Thus, for instance, a user-specific scaling can be enabled for the analog I/Os.

The feature register specifies the terminal's operation mode. [0x0106]

Feature bit no.

 

Description of the operation mode

Bit 0

1

User scaling (R33, R44) active [0]

Bit 1

1

Manufacturer scaling (R19, R20) active [1]

Bit 2

1

Watchdog timer active [1]
In the delivery state, the watchdog timer is switched on.

Bit 3

1

Signed amount representation [0]
Signed amount representation is active instead of two's-complement representation (-1 = 0x8001).

Bit 4

1

Siemens output format [0]
This bit is used for inserting status information on the lowest 3 bits (see below).

Bit 5, 6

-

reserved, do not change

Bit 7

1

activates filter constant in R37 [0]

Bit 8

1

Overrange Protection [1]
If the temperature exceeds 850 °C the status bits are correspondingly set and the output value is restricted to 850 °C.

Bit 9

-

reserved, do not change

Bit 10

1

Two-wire connection [0]

Bit 11

-

reserved, do not change

Bit 12, 13, 14, 15

Element

Valid measuring range

0 0 1 0

PT1000

0 °C ... 40 °C

0 1 0 1

NI1000

0 °C ... 40 °C

Output format

If only manufacturer scaling via the feature register is active, the output format is as follows:
1 digit is equivalent to 1/10 °C or
1 digit is equivalent to 1/10 Ω

If no scaling is active, the output format is as follows:
1 digit is equivalent to 1/16 °C or
1 digit is equivalent to 1/16 Ω

If the Siemens output format is selected, the lowest three bits are used for status evaluation. The process data is mapped in bits 3 to 15, with bit 15 representing the sign bit. Scaling of the measurement reading according to the Siemens standard has to be done via user scaling.

Measured value

Bit 15-3

Bit 2
X

Bit 1
Error

Bit 0
Overflow

out of range

 

0

0

1

in range

Process data

0

0

0

R33 to R47: Terminal-specific registers

The function of these registers depend on the respective terminal type (see terminal-specific register description).

R33: User scaling – offset (B_w)

16-bit signed integer
This register contains the offset of the user straight-line equation (1.6). The linear equation is enabled via register R32.

R34: User scaling (A_w)

16-bit signed integer * 2-8. This register contains the scaling factor of the user straight-line equation (1.6). The linear equation is enabled via register R32.

R35 and R36: reserved

R37: Filter constant

[0x0000]
This documentation applies to all terminals from firmware version 3x. The version number can be found within the serial number on the right-hand side face of the terminal: xxxx3xxx

Example: 52983A2A = the firmware version is 3A.

Filter constant

First notch [Hz]

Conversion time [ms]

0x0000

25

250

0x50

100

65

0xA0

50

125

0x140

25

250

0x280

12.5

500