Modbus analog input and output points

Modbus analog point syntax

Telem_Server_<ScopeName>:%<GroupName.OutstationName>;<PointType>;<PointAddress>;<DataType>{;ZSValue}{;FSValue}{;DBValue}{%}{;[PointName]}

• PointType: AI or AO

• PointAddress: a 5 or 6 digit decimal number, depending on the Point Address Range setting of the outstation. The default setting is 5 digits. The range of valid addresses vary by point type and maps to the "Address" field in the Telemetry Server dashboard.

• DataType: one of the values listed in the following table, for example UINT16.

  Data type	Definition
  UINT16	Unsigned 16-bit integer
  UINT32	Unsigned 32-bit integer
  INT16	Signed 16-bit integer
  INT32	Signed 32-bit integer
  SINGLE	Single precision float
  DOUBLE	Double precision float

• Optional fields: ZSValue, FSValue, DBValue, and PointName. You can enter these fields in any order. If no value is entered, the default values for these fields are used.

  • ZSValue: This sets the zero scale limit of the tag in the Telemetry Server, and uses the format "ZS<value>", where <value> is a double data-type value and includes both positive and negative numbers. If <value> is out of range, point creation fails.

  • FSValue: This sets the full scale limit of the tag in the Telemetry Server. It uses the format "FS<value>", where <value> is a double data-type value and includes both positive and negative numbers. If the value given is out of the range, point creation fails.

  • DBValue: This sets the Significant Change option (deadband) of the tag in the Telemetry Server. You can enter the deadband as an absolute or percentage value, as follows:

    • DB<value> sets the Significant Change field to Absolute, and sets the Deadband field to <value>.

    • DB<value>% sets the Significant Change field to Percentage of Change, and sets the Deadband field to <value>.

    • The <value> specified for both Absolute and Percentage of Change must be a positive double data-type value.

    • When Percentage of Change is used, the maximum value is 100.

  • PointName: a descriptive name for the point, for example, [LiftStationPump_01]. If specified, the PointName must be enclosed in brackets.

    • If PointName is not specified, the point is assigned a default name that uses point type and number, in the format PointType_PointNumber, for example, AI_100.

    • If you want to create the new point in a different group than the Outstation group, include the group name: GroupName.PointName.

Analog reference examples

Without optional parameters:

Telem_Server_Node-12:%Group.Modbus_RTU;AI;40001;UINT16

References the analog input point mapped to holding register 40001with UINT16 data type, which is given the name AI_40001

With the optional zero scale, full scale, and deadband parameters:

Telem_Server_Node-12:%Group.Modbus_RTU;AI;40001;UINT16;ZS-10;FS250;DB25%

References the same analog input point as above, but defines the zero scale limit as -10, the full scale limit as 250, and the deadband as 25%

With the optional point name parameter (include the group name when creating the point in a different group than the Outstation)::

Telem_Server_Node-12:%Group.Modbus_RTU;AI;40001;UINT16;[Group2.Point_Name]

References the analog input point mapped to holding register 0001 with UINT16 data type, which is named Point_Name and is created in Group2.