Siemens S7 Alarm and Events

Alarm Address

The Address for the alarms is following:

Address	Description	Data Type
Plc1.OEMAlarmEvent:0	System Alarm and operator message reader.	TAlarmEvent[]

Messages are not acknowledged by the HumanOS® IoT Platform. Typically, this is done by the machine component when its associated reset action is activated.

Alarm Item

See the Operation Manual for the containing fields.

Alarm Tasks and Mapping

The driver supports PLC alarms by mapping source.

It is possible to declare multiple alarm sources (tasks) for one alarm address (pool).

This example shows three alarm sources with a mapping file:

{
  "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"
          }
        ]
      }
    ]
  }
}

Accessor	Description
Id	Unique Id for each task
Name	A name for the task
Address	Alarm address (pool)
Property MessageMappingFile	The mapping file to load (copy to The mapping file to load - copy to .\Config\HumanOS.UHAL.SiemensS7Control\)
Property MessageCount	Amount of messages which are mapped (depends on the Property MessageFormat)
Property StartAddress	The corresponding source address with offset and length (depends on the Property MessageFormat)
Property MessageFormat	BitMessage or Channel32Message
Property Message:Type	Type of each message that occurs from this source

A property which starts with Message: is attached as property to the alarm item (e.g. message) which means additional fields are added with this data and can be used later on.

Mapping means, the alarms and events are defined by the data given and not the data that the alarm source provides.
The mapping source must either be of type JSON and must be structured like this example:

{
  "Messages": [
    {
      "Id": 0,
      "AlarmType": "Alarm",
      "OemId": "Alarm 1",
      "Text": "PU Sammelfehler",
      "Properties": [
        {
          "Name": "MyProperty",
          "Value": "Some other info"
        },
        {
          "Name": "EnableRmq",
          "Value": "1"
        },
        {
          "Name": "EnableRest",
          "Value": "0"
        }
      ]
    }
  ]
}

Accessor	Description
Id	Specifies the bit number (absolute)
AlarmType	Specifies the Alarm type, see Alarm Types in Alarm and Event Source
OemId	The Condition name of the alarm or event
Text	Specifies the message
Properties	Specify properties which are attached to this alarm or event and can later be accessed
Properties:Name	Property name
Properties:Value	Property value

Example in the designer:

Calculation of MessageCount

The "MessageCount" together with the "MessageFormat" specifies the amount of data to be read.

MessageFormat	Description
BitMessage	The entered value is divided by 8 and rounded to the next bigger number of 8*value to specify the number of bytes to be read, the raw value is mapped to the message file
Channel32Message	The entered value is multiplied by 4 to specify the number of bytes to be read, the raw value is mapped to the message file

Bitmessage

Examples BitMessage:

Entered Value	Number of bytes read by driver	Mapped messages (bits)
0	0	0
2	1	2
8	1	8
9	2	9
200	25	200
1056	132	1056

Channel32Messages

Each segment displays a bit and a bit equals a channel, so for example if there are 32 error LEDs on a device each segment could be one LED. The 32-bit channel messages allow bundling of errors of the same type. One error text will then be applied for all 32 bits, with the channel id automatically attached.

Examples Channel32Message:

Entered Value	Number of byes read by driver	Mapped messages	Mapped bits
0	0	0	0
1	4	1	32
4	16	4	128
9	36	9	288
16	64	16	512
33	132	33	1056

Calculation of StartAddress

The "StartAddress" specifies the source, offset and length of the data array.

It is possible and needed by Channel32Messages to specify a higher length than the "MessageCount". The suggestion is to calculate the "MessageCount" and adapt the value in the brackets to avoid conflicts.

BitMessage:

Calculation	Example
MessageCount / 8 -> round to next bigger whole number	20/8=2.5 -> 3 Bytes
Length * 8	3*8=24 Messages/Bits

Channel32Message:

Calculation	Example
MessageCount * 4	10*4=40 Bytes
Length / 4	40/4=10 Messages/Bits

The address Plc1.DataBlock.ByteArray:972.0[48] means:

• Source: DataBlock
• DataType: ByteArray
• Source Number: 972
• Offset in byte: 0
• Length in byte: 48

Examples:

Bracket Value (Array Length)	MessageCount	MessageFormat	Resulting Length in bytes
1	1	BitMessage	1
4	1	BitMessage	1
16	16	BitMessage	2
16	128	BitMessage	16
4	1	Channel32Message	4
8	2	Channel32Message	8
132	2	Channel32Message	8