Configuration of analog value display

Description

The product offers the possibility to display the digitalized value in different formats.

The following settings are available:

  • Resolution

  • Alignment

  • Data format

Resolution

The product can display the digitalized values with different resolutions in the process data. The resolution can be set independently for each port:

  • 10 Bit

  • 12 Bit

  • 14 Bit

  • 16 Bit

Alignment

The digitalized data is always sent or received in 16-bit units. If the resolution is less than 16 bits, it is possible to set the alignment of the data. This setting then applies to all ports.

Left-aligned data for different resolutions:

Configuration of analog value display – Left-aligned data

Bit

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

MSB 10 bit data

[1]

MSB 12 bit data

[1]

MSB 14 bit data

[1]

MSB 16 bit data

Right-aligned data:

Configuration of analog value display – Right-aligned data

Bit

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

[1]

MSB 10 bit data

[1]

MSB 12 bit data

[1]

MSB 14 bit data

MSB 16 bit data

Data format

The digitalized value can be represented in three data formats. Either as an N-bit unsigned or signed value (two’s complement) or as a value with the unit of millivolt [mV] or microampere [µA].

Note

If the unit (millivolt [mV] or microampere [µA]) is selected for the display, then the resolution and alignment settings have no effect on the process data.

Calculation of the digitalized value

To determine the exact value of the input and output signal, digitalized values must be calculated using different formulas depending on the data setting and port type.

Formula for voltage signals 0…10V, −10…+10V, 0…+5V, −5…+5V, signed format

For positive values (MSB = 0):

\[\text{Input voltage [V]}=\text{Digitalized value} \cdot\frac{V_{max}}{2^{(N-1)}-1}\]

For negative values (MSB = 1):

\[\text{Input voltage [V]}=(\text{Digitalized value}-2^N) \cdot\frac{V_{max}}{2^{(N-1)}-1}\]

  • N: Resolution 16, 14, 12 or 10 bit (depending on configuration)

  • Digitalized value: 16, 14, 12 or 10-bit value in the process data

  • V: Maximum input voltage for the selected input max range (measuring range). e.g. +11.759V for a nominal range of 0…10V

Formula for voltage signal 5…10V, 1…5V, signed format

\[\text{Input voltage [V]} = \text{Digitalized value}\cdot\frac{V_{max}-V_{min}}{2^{(N-1)}-1}+V_{min}\]

  • N: Resolution 16, 14, 12 or 10 bit (depending on configuration)

  • Digitalized value: 16, 14, 12 or 10-bit value in the process data

  • Vmax: Maximum input voltage for the selected input max range (measuring range). e.g. +11.759V for a nominal range of 5…10V

  • Vmin: Minimum input voltage for the selected nominal input range. e.g. +5V for a range of 5…10V

Formula for current signal 0…20mA, 4…20mA, signed format

\[\text{Input current [mA]} = \text{Digitalized value}\cdot\frac{I_{max}-I_{min}}{2^{(N-1)}-1}+I_{min}\]

  • N: Resolution 16, 14, 12 or 10 bit (depending on configuration)

  • Digitalized value: 16, 14, 12 or 10-bit value in the process data

  • Imax: Maximum input current for the selected input max range (measuring range). e.g. 22mA for a nominal range of 0…20mA

  • Imin: Minimum input current for the selected nominal input. e.g. 4mA for a nominal range of 4…20mA

Note

Nominal and measuring range start at 0 mA. Because the module cannot measure negative currents, the underflow detection does not work for the nominal range 0…+20 mA.

Formula for voltage signals 0…10V, −10…+10V, 0…+5V, −5…+5V, 1V…5V unsigned format

\[\text{Input voltage [V]}=\text{Digitalized value} \cdot\frac{V_{max}-V_{min}}{2^{(N)}-1}+V_{min}\]

  • N: Resolution 16, 14, 12 or 10 bit (depending on configuration)

  • Digitalized value: 16, 14, 12 or 10-bit value in the process data

  • Vmax: Maximum input voltage for the selected input max range (measuring range). e.g. +11.759V for a nominal range of 5…10V

  • Vmin: Minimum input voltage for the selected input max range (measuring range). e.g. +4.12V for a nominal range of 5…10V

Formula for current signal 0…20mA, 4…20mA, unsigned format

\[\text{Input current [mA]} = \text{Digitalized value}\cdot\frac{I_{max}-I_{min}}{2^{(N)}-1}+I_{min}\]

  • N: Resolution 16, 14, 12 or 10 bit (depending on configuration)

  • Digitalized value: 16, 14, 12 or 10-bit value in the process data

  • Imax: Maximum input current for the selected input max range (measuring range). e.g. 22mA for a nominal range of 4…20mA

  • Imin: Minimum input current for the selected input max range (measuring range). e.g. 2mA for a nominal range of 4…20mA

Note

For further information of minimum and maximum input values to calculate with in the equations above, please refer to Configuration of analog ports - Nominal and measuring range.

Formula for voltage signals, format as value with unit

For positive values (MSB = 0):

\[\text{Input voltage [V]} = \frac{\text{Digitalized value [mV]}}{1000}\]

For negative values (MSB = 1):

\[\text{Input voltage [V]} = \frac{(\text{Digitalized value}-65536)[mV]}{1000}\]

Note

If Value with unit is selected as format, all 16 bits of the process data for the respective port must be used for the digitalized value for calculation.

Formula for current signals, format as value with unit

For positive values (MSB = 0):

\[\text{Input current [mA]} = \frac{\text{Digitalized value [μA]}}{1000}\]

Note

If Value with unit is selected as format, all 16 bits of the process data for the respective port must be used for the digitalized value for calculation.

Examples

1st example:

The input port has -10V…+10V set as the nominal range. The resolution is 16 bit, the data format is signed. The digitalized value in the input process data is 0x0ADD = 2781.

The bit with the highest significance (MSB) of 0x0ADD is 0, i.e. a positive number. In this case the voltage can be calculated with the following formula:

\[\begin{split}\text{Input voltage [V]}&=\text{Digitalized value} \cdot\frac{V_{max}}{2^{(N-1)}-1}=\\ &=2781\cdot\frac{11.759V}{2^{(16-1)}-1}=0,998V\end{split}\]

2nd example:

The input port has −5V…+5V set as the nominal range. The resolution is 16 bits, the data format is signed. The digitalized value in the input process data is 0xD472 = 54386.

The bit with the highest significance (MSB) of 0xD472 is 1, i.e. a negative number. In this case the voltage can be calculated with the following formula:

\[\begin{split}\text{Input voltage [V]} &=(\text{Digitalized value}-2^N) \cdot\frac{V_{max}}{2^{(N-1)}-1}=\\ &=(54386-2^{16})\cdot\frac{5.879V}{2^{(16-1)}-1}=-2.000V\end{split}\]

3rd example:

The input port has 5V…+10V set as the nominal range. The resolution is 16 bits, the data format is signed. The digitalized value in the input process data is 0x302F = 12335.

The bit with the highest significance (MSB) of 0x302F is 0, i.e. a positive number. In this case the voltage can be calculated with the following formula:

\[\begin{split}\text{Input voltage [V]} &=(\text{Digitalized value}) \cdot\frac{V_{max}-V_{min}}{2^{(N-1)}-1}+V_{min}=\\ &=(12335)\cdot\frac{11.759V-5V}{2^{(16-1)}-1}+5V=7.5449V\end{split}\]

4th example:

The input port has 4mA…20mA set as the nominal range. The resolution is 16 bits, the data format is unsigned. The digitalized value in the input process data is 0x4CC8 = 19656.

In this case the current can be calculated with the following formula:

\[\begin{split}\text{Input current [V]} &=(\text{Digitalized value}) \cdot\frac{I_{max}-I_{min}}{2^{(N-1)}-1}+I_{min}=\\ &=(19656)\cdot\frac{22mA-2mA}{2^{(16-1)}-1}+2mA=13.997mA\end{split}\]

5th example:

The output port has 4mA…20mA set as the nominal range. The resolution is 16 bits. The data format is unsigned.

If an output current of 14mA is necessary, the output process data can be calculated with the following formula:

\[\begin{split}\text{PD out} &=(\text{Output current}-I_{min})\cdot\frac{2^{N}-1}{I_{max}-I_{min}}=\\ &=(14mA-4mA)\cdot\frac{2^{16}-1}{20mA-4mA}=40959\end{split}\]

6th example:

The output port has 4mA…20mA set as the nominal range. The resolution is 16 bits. The data format is signed.

If an output current of 14mA is necessary, the output process data can be calculated with the following formula:

\[\begin{split}\text{PD out} &=(\text{Output current}-I_{min})\cdot\frac{2^{(N-1)}-1}{I_{max}-I_{min}}=\\ &=(14mA-4mA)\cdot\frac{2^{(16-1)}-1}{20mA-4mA}=20479\end{split}\]

7th example:

The output port has 1V…5V set as the nominal range. The resolution is 16 bits. The data format is unsigned.

If an output voltage of 2V is necessary, the output process data can be calculated with the following formula:

\[\begin{split}\text{PD out} &=(\text{Output voltage}-V_{min})\cdot\frac{2^{N}-1}{V_{max}-V_{min}}=\\ &=(2V-1V)\cdot\frac{2^{16}-1}{5V-1V}=16384\end{split}\]

Process Data

Configuration of analog value display – Process Data

Name

Description

Direction

Digitalized input value at Port 1

16 digitalized input values

Output

Digitalized input value at Port 2

16 digitalized input values

Output

Digitalized input value at Port 3

16 digitalized input values

Output

Digitalized input value at Port 4

16 digitalized input values

Output

Digitalized input value at Port 5

16 digitalized input values

Input

Digitalized input value at Port 6

16 digitalized input values

Input

Digitalized input value at Port 7

16 digitalized input values

Input

Digitalized input value at Port 8

16 digitalized input values

Input

ISDU

Configuration of analog value display – ISDU

Name

Index

Subindex

Access

Length

Data Type

Data Storage

Default

Process Data Allignment

0x59 (89)

0

R/W

1 Byte

UINT8

Yes

0x01

Resolution

0xF1 (241)

0

R/W

8 Byte

Yes

Resolution Port x

1…8

R/W

1 Byte

UINT8

No

0x00

Process Data Format

0xF5 (245)

0

R/W

8 Byte

Yes

Process Data Format Port x

1…8

R/W

1 Byte

UINT8

No

0x00

Process Data Alignment

Configuration of analog value display – Process Data Alignment

Value

Meaning

0x00 (0)

Left-aligned

0x01 (1)

Right-aligned

Resolution

Configuration of analog value display – Resolution (Subindex)

Subindex

Meaning

1

Resolution Port 1

2

Resolution Port 2

3

Resolution Port 3

4

Resolution Port 4

5

Resolution Port 5

6

Resolution Port 6

7

Resolution Port 7

8

Resolution Port 8

The following values can be set:

Configuration of analog value display – Resolution

Value

Meaning

0x00 (0)

16 Bit

0x01 (1)

14 Bit

0x02 (2)

12 Bit

0x03 (3)

10 Bit

The default value for all ports is: 0x00, the resolution is 16 bit.

Process Data Format

Configuration of analog value display – Process Data Format (Subindex)

Subindex

Meaning

1

Data format Port 1

2

Data format Port 2

3

Data format Port 3

4

Data format Port 4

5

Data format Port 5

6

Data format Port 6

7

Data format Port 7

8

Data format Port 8

The following values can be set:

Configuration of analog value display – Process Data Format

Value

Meaning

0x00 (0)

N-bit signed value

0x01 (0)

N-bit unsigned value

0x02 (1)

Unit mV or µA

The default value for all ports is: 0x00, the data format of all ports is N-bit signed.

Note

For the analog input ports the N-bit unsigned value is not available.

System Commands

Configuration of analog value display – System Commands

Command Value

Device Action

0x81 (129)

Application Reset – Resets writable parameters to the default value.

0x82 (130)

Reset Factory Settings – Resets writable parameters to the default value.