Version: 2.7

Siemens S7 Data Access

This chapter outlines all possible native addresses. These addresses must be configured within the device configuration.

Format

A native Siemens S7 address has following format:

{memory base}.{memory type}.{data type}:{address}

{address} = {MemoryTypeNumber}.{MemoryTypeOffset}.{SliceAccessor}

Example: Plc1.DataBlock.Float32:118.14

This will read 4 Bytes (Float32) of data block (DB) 118 with Offset 14.

Example: Plc1.DataBlock.Bool:118.14.0

This will read the first bit of 1 Byte at offset 14 of data block (DB) 118.

In case of Input or Output Memory input value 0 at the memory type section.

The slice accessor is optional and only valid if a bit is declared as data type. It must be a value between 0 and 7.

Or in case of a single variable:

{memory base}.{memory type}.{data type}:{variable name}

Memory Base

As a Plc only has one memory channel the resulting memory base is always Plc1 (except for diagnosis values):

Memory Channel	Description
Plc1	PLC 1 memory base
Global	Global memory base

Memory Type

The PLC control provides different channels for memory:

Memory Channel	Description
Input	Global Input Memory (only available in Plc1 memory base)
Output	Global Output Memory (only available in Plc1 memory base)
DataBlock	Global DataBlock Memory (only available in Plc1 memory base)
Memory	Global Memory (User constants, Global Variables, ...; only available in Plc1 memory base)
Timer	Global Timer Memory (only available in Plc1 memory base)
Counter	Global Counter Memory (only available in Plc1 memory base)
Diag	Global Diagnosis Values (only available in Global memory base)

Data Types

Data types are part of a HumanOS® data address. Common conversions are:

Data Type (Siemens)	Description	System Data Type	HumanOS® Adress Data Type
BOOL	Bit information. 0 = not set; 1 = set	System.Boolean	Bool
BYTE	Byte information (unsigned 8bit integer)	System.Byte	Uint8
SINT	Byte information (signed 8bit integer)	System.Int8	Int8
USINT	Byte information (unsigned 8bit integer)	System.UInt8	Uint8
WORD	Word information (unsigned 16bit integer)	System.UInt16	Uint16
INT	Int information (signed 16bit integer)	System.Int16	Int16
UINT	Uint information (unsigned 16bit integer)	System.UInt16	Uint16
DWORD	Dword information (unsigned 16bit integer)	System.UInt32	Uint32
DINT	Dint information (signed 32bit integer)	System.Int32	Int32
UDINT	Udint information (unsigned 32bit integer)	System.UInt32	Uint32
REAL	Floating point number (signed 32bit)	System.Single	Float32
LREAL	Floating point number (signed 64bit)	System.Double	Float64
LWORD	Lword information (unsigned 64bit integer)	System.UInt64	Uint64
LINT	Lint information (signed 64bit integer)	System.Int64	Int64
ULINT	Ulint information (unsigned 64bit integer)	System.UInt64	Uint64
ARRAY OF BYTE	Array of Bytes (Array of unsigned 8bit integer)	`System.Byte[]`	ByteArray
STRING / STRING[n]	String information	System.String	String

INFORMATION

Strings must be specified from their address offset. See example in memory configuration datablock. Ignoring to do so will result in faulty values. If the string is specified with a length indicator in the plc, remember to calculate your length => string[x] : x+2 bytes

Memory Type Number

The memory type number is limited by the memory type:

INFORMATION

Memory ranges depend on the memory type:

Input/Output: always 0

DataBlock/ Memory/Timer/Counter: 0-65535

Memory Type Configuration

Input

The input channel can only be read or monitored. Writing is not possible.

Address Example	Description	Data Type
`Plc1.Input.Float32:0.14`	Reads 4 Bytes from I 14.0	System.Double
`Plc1.Input.Bool:0.1`	Reads second bit from first byte	System.Boolean

Output

The configuration can only be read or monitored. For writing, use the appropriate command.

Address Example	Description	Data Type
`Plc1.Output.Float32:0.14`	Reads 4 Bytes from Q 14.0	System.Double

DataBlock

The values can only be read or monitored. For writing, use the appropriate command.

Address Example	Description	Data Type
`Plc1.DataBlock.Float32:100.14`	Reads 4 Bytes from DB 100 offset 14	System.Double
`Plc1.DataBlock.String:2.20[4]`	Reads a string with length of 2 Bytes (offset 22) from DB 2 offset 20	System.String
`Plc1.DataBlock.Bool:2.0.1`	Reads second bit from first byte from DB 2	System.Boolean

Counter

The values can only be read or monitored. This does not work on all cpus.

Address Example	Description	Data Type
`Plc1.Counter.Int32:1`	Reads the global counter value from C1	System.Int32

Timer

The values can only be read or monitored. This does not work on all cpus.

Address Example	Description	Data Type
`Plc1.Timer.Int32:1`	Reads the global timer value from T1	System.Int32

Memory

The values can only be read or monitored.

Address Example	Description	Data Type
`Plc1.Memory.Int32:1`	Reads the global Memory from Byte 1 -- see the appropriate Memory location in the PLC for Offsets	System.Int32

Variable

CAUTION

Variables are very inefficient in terms of speed. A separate call is made to the PLC for each variable. Use memory types if possible.

INFORMATION

All 64-bit values are not supported.

The values can only be read or monitored. For writing, use the appropriate command. Reading arrays is not possible (Strings also count as arrays), use the appropriate memory type for that.

Address Example	Description	Data Type
`Plc1.Variable.Uint16:DB10.DBW20`	Reads the Word with offset 20 in the DB 10	System.Uint16
`Plc1.Variable.Int16:DB10.DBW20`	Reads the int with offset 20 in the DB 10	System.Int16
`Plc1.Variable.Int32:DB2.DBD1338`	Reads the int with offset 1338 in the DB 2	System.Int32
`Plc1.Variable.Float32:DB2.DBD14`	Reads the float with offset 14 in the DB 2	System.Single
`Plc1.Variable.Bool:DB2.DBX0.0`	Reads the first bool with offset 0 in the DB 2	System.Boolean
`Plc1.Variable.Uint8:DB2.DBB1320`	Reads the byte with offset 1320 in the DB 2	System.Byte
`Plc1.Variable.Int8:DB2.DBB1342`	Reads the int with offset 1342 in the DB 2	System.Int16

Accepted data and memory type definitions

Definer(s)	Memory Type	Data Length (bytes)
DBB	Datablock	1
DBW	Datablock	2
DBD	Datablock	4
DBX	Datablock	1 (reads bit x from 1 byte)
IB / EB	Input	1
IW / EW	Input	2
ID / ED	Input	4
E / I	Input	1 (reads bit x from 1 byte)
QB / AB / OB	Output	1
QW / AW / OW	Output	2
QD / AD / OD	Output	4
Q / A / O	Output	1 (reads bit x from 1 byte)
MB	Global Memory	1
MW	Global Memory	2
MD	Global Memory	4
M	Global Memory	1 (reads bit x from 1 byte)

Diag

The values can only be read or monitored. Supported values are:

Address Example	Description	Data Type
`Global.Diag.Int32:1`	Connection status to PLC (1=Connected)	System.Int32
`Global.Diag.Int32:2`	Connection life bit (toggling in 1Hz)	System.Int32

Device Info Example

{
  "Id": "d5baf54a-10e6-4cf4-866e-bfbae46e01c2",
  "Name": "S7 Control",
  "DriverId": "F25F68F9-C720-4DD9-8A28-957C84AAA98C",
  "Address": "Cpu=S7400;Address=192.168.44.86;Rack=0;Slot=5",
  "Properties": [
    {
      "Name": "TcpTimeout",
      "Value": 5000,
      "DataType": "System.Int32"
    }
  ],
  "DataNodes": [
    {
      "Id": "a89475ce-66c2-4025-acba-e96b9ed5921d",
      "Name": "MyValues",
      "DataType": "System.Double",
      "DataClass": "Event",
      "Address": "Plc1.DataBlock.Float32:151.14",
      "Access": {
        "Read": true,
        "Receive": true
      }
    }
  ],
  "AlarmEventPool": {
    "Id": "0efafbcd-447a-4fb6-900d-51affdc25e8f",
    "Name": "Alarming",
    "HistoryMode": {
      "Retention": 20,
      "SamplingRate": 2000
    },
    "Tasks": [
      {
        "Id": "66d0a44d-83e8-494d-9e15-5af16df60d55",
        "Name": "Alarm Messages",
        "Address": "Plc1.OEMAlarmEvent:0",
        "Properties": [
          {
            "Name": "MessageMappingFile",
            "Value": "Signallist.json"
          },
          {
            "Name": "MessageCount",
            "Value": 187,
            "DataType": "System.Int32"
          },
          {
            "Name": "StartAddress",
            "Value": "Plc1.DataBlock.ByteArray:970.0[47]"
          },
          {
            "Name": "MessageFormat",
            "Value": "BitMessage"
          },
          {
            "Name": "Message:Type",
            "Value": "Raise"
          }
        ]
      },
      {
        "Id": "f2280557-9806-414d-b002-aa3e30fb79b5",
        "Name": "Alarm Confirm Messages",
        "Address": "Plc1.OEMAlarmEvent:0",
        "Properties": [
          {
            "Name": "MessageMappingFile",
            "Value": "Signallist.json"
          },
          {
            "Name": "MessageCount",
            "Value": 187,
            "DataType": "System.Int32"
          },
          {
            "Name": "StartAddress",
            "Value": "Plc1.DataBlock.ByteArray:971.0[47]"
          },
          {
            "Name": "MessageFormat",
            "Value": "BitMessage"
          },
          {
            "Name": "Message:Type",
            "Value": "Confirm"
          }
        ]
      }
    ]
  }
}

Format​

Memory Base​

Memory Type​

Data Types​

Memory Type Number​

Memory Type Configuration​

Input​

Output​

DataBlock​

Counter​

Timer​

Memory​

Variable​

Accepted data and memory type definitions​

Diag​

Device Info Example​

Format

Memory Base

Memory Type

Data Types

Memory Type Number

Memory Type Configuration

Input

Output

DataBlock

Counter

Timer

Memory

Variable

Accepted data and memory type definitions

Diag

Device Info Example