<< Back to GIL Documentation

Signal Exchange List (SEL)

The Signal Exchange List defines which process data to be interchanged between the External system and the Process model.

! This is an example signal exchange list. 
!---------------------------- Mandatory attributes ----------------------------------|---- Custom attributes ----|
Type     DataType        Length  Direction PMID       ESID        Description          ESMin   ESMax  PMMin  PMMax
Analog   Float32         1       ToPM      test0      evar1       "Example signal 0"   0       20     100     500
Analog   Float32         6       ToPM      testA      evarA       "An array example"   --      --     --      --
Analog   Float32         1       ToPM      test1      evar1       "Example signal 1"   0       20     100     500
Analog   Float32         1       ToES      test2      evar2       "Example signal 2"   4       20     0       100
Analog   Float32         8       ToES      testA1     evarA2      "An array example"   --      --     --      --
Analog   Float32         1       ToES      test3      evar3       "Example signal 3"   4       20     0       100

Each signal in the SEL consists of a number of defined attributes. There are mandatory attributes and custom attributes. Mandatory attributes are always present in the SEL contrary to custom attributes which depends on the adaptations made to a certain installation of GIL. GIL has no knowledge of how to interpret custom attributes. GIL just parses the attributes and delegates them to the stages in the transfer pipeline, the ES-adapter and PM-adapter. It is then up to each stage and adapter to interpret the attributes. In the example above there are four custom attributes ESMax, ESMin, PMMAx and PMMin. These attributes define ranges for the ConvertStage to convert values from electrical to engineering units.

Mandatory attributes

TypeCan be either Analog or Digital. Analog defines a continuous value and Digital a value that can be either true or false (1=true, 0=false).
DataTypeDefines the primitive data type:
  • Float32
  • Float64
  • Int8
  • Int16
  • Int32
LengthThe number of elements of the given DataType. Example use is to transfer an array of values.
DirectionDefines the direction of flow:
  • ToPM - process data is transferred from the external system to the process model
  • ToES - process data is transferred from the process model to the external system
PMIDIdentifies the signal for the process model adapter.
ESIDIdentifies the signal for the external system adapter.
DescriptionAn arbitrary, more verbose description of the signal.

Details

The SEL file can have a arbritrary name and path but by convention the filename extension should be '.sel'. On a GIL installation the SEL path is set in the gil.config.xml file.

The header of the SEL consists of a minimum of seven columns, which must be present in the top of the file. Besides these seven mandatory columns there may be a arbitrary set of custom attribute columns. Subsequent lines must comprise the same numbers of colums as the header. Colums are separated by blank characters such as spaces or tabs. Column entries containing blanks must be enclosed in quotation marks e.g. "An entry with spaces".

You can avoid setting values for custom attributes by entering --.

 Type   DataType Length Direction PMID  ESID   Description  MaxValue MinValue
 Analog Float32  1      ToES      anId1 anID2  "a descr"    --       --

Exclamation mark ! is used for single line comments

! This is a single line comment