Description | Example | Return Message | Group

Comm Define (Transmitter)

Set the basic properties of a transmitter (Deprecated Command)

Syntax

Comm <XmObjectPath> Define XmtrModel {XmType} {ModelType} <Parameters>

ATTENTION: THIS COMMAND IS DEPRECATED and has been replaced by:

Transmitter

Description

Note: This command was deprecated in STK 9, it should no longer be used. This command has been replaced by the Transmitter command.

The Comm Connect commands were enhanced in STK 9 to make use of attributes and to simplify the format required to use these commands. For more information on using the new format with the Transmitter command, see Transitioning to the New Transmitter Connect Format.

The Comm Define commands allows you to define the basic properties of the specified transmitter. {XmType} can be either Source or Retrans. Any communications link analysis scenario must contain at least one Source transmitter.

Valid values for {XmType} are described in this table.

{XmType} Description
Source Source transmitters are used to model the originating node of a communications link since they define some fundamental parameters for the link such as data rate and modulation type.
Retrans Retransmitters are used to modify a received signal and retransmit it.

Valid values for {ModelType} are described in this table.

{ModelType} Description
Simple Use the Simple model type if you don't have all the information necessary to model a transmitter at a detailed level. This is a common occurrence during the systems engineering process.
Medium Use the Medium model type if you need a little more flexibility than that provided by the Simple model.
Complex Use the Complex model to specify a particular antenna type, whether it is one of the predefined antennas or an antenna defined in an external file.
Multibeam Use the Multibeam model to specify a transmitter configured for multiple antenna beams.
Laser Use the Laser model, in combination with the Laser Receiver model, to facilitate communications laser link budget analysis.
Cable Use the Cable model to define a transmitter that is physically connected to the receiver by some type of "fixed line medium," such as wire, coaxial cable, twisted-pair cable, CAT-5, fiber optic silica, etc.

Note: The Cable {ModelType} is available only for a transmitter whose parent object is a facility or target.

GPS Models a satellite GPS antenna.
Plugin Source transmitter defined in user-supplied script.

Source Transmitters

If you specify Source as the {XmType}, {ModelType} remains Simple, Medium, Complex, MultiBeam or Laser but parameters differ from retransmitters. <DataRate> corresponds to the raw data rate after any Forward Error Correction (FEC) encoding has been performed.

Hint: Once you set the basic parameters for a Transmitter model using this command, use the commands listed in the Related Commands list above and Graphics (Comm) command to further define the transmitter.

At least one <Parameters> must be entered for each Comm Define command.

{ModelType} <Parameters> Description
Simple Frequency <Value> A numeric value entered in Scenario Frequency units, 0.1 to 1e+015 Hz
EIRP <Value> A numeric value entered in Scenario Power units, -2890.0 to 2890.0 dBW
Medium Frequency <Value> A numeric value entered in Scenario Frequency units, 0.1 to 1e+015 Hz
Gain <Value> A numeric value entered dB, -2890.0 to 2890.0 dB
Power <Value> A numeric value entered in Scenario Power units, -2890.0 to 2890.0 dBW
Complex Frequency <Value> A numeric value entered in Scenario Frequency units, 0.1 to 1e+015 Hz
Power <Value> A numeric value entered in Scenario Power units, -2890.0 to 2890.0 dBW
MultiBeam {Add | Modify | Delete} <BeamID> [<BeamParameters>] Valid <BeamParameters> are:
  • Frequency <Value>
  • Power <Value>
  • Active {Yes | No}

The Frequency <Value> is entered in Scenario Frequency units, 0 to 1e+015 Hz

The Power <Value> is entered in Scenario Power units, -2890.0 to 2890.0 dBW

If Add is specified then none or any <BeamParameters> can be included with the command. If Modify is specified then at least one <BeamParameters> must be included on the command line. If Delete is specified then no <BeamParameters> should be included.

Laser Frequency <Value> A numeric value entered in Scenario Frequency units, 1e+012 to 1e+017 Hz
Gain <Value> A numeric value entered dB, -2890.0 to 2890.0 dB
Power <Value> A numeric value entered in Scenario Power units, -2890.0 to 2890.0 dBW
Cable DataRate <Value> Enter a numeric value in Mb/sec. The value must be between 1.0e-12 to 1.0e+6
ChipRate <Value> Enter an integer value between 1 and 1000000
GPS {Add | Modify | Delete} <BeamID> [<BeamParameters>] Valid <BeamParameters> are:
  • Frequency <Value>
  • Power <Value>
  • Active {Yes | No}

The Frequency <Value> is entered in Scenario Frequency units, 0 to 1e+015 Hz

The Power <Value> is entered in Scenario Power units, -2890.0 to 2890.0 dBW

If Add is specified then none or any <BeamParameters> can be included with the command. If Modify is specified then at least one <BeamParameters> must be included on the command line. If Delete is specified then no <BeamParameters> should be included.

Plugin "<Filename>" Enter the full file path and name to be used to define the transmitter. The file is an external script, such as MATLAB, VBScript and Perl scripts, that defines the transmitter.

Retransmitter

If you specify Retrans as the {XmType}, {ModelType} can be Simple, Medium or Complex, but parameters differ from source transmitters.

Hint: Once you set the basic parameters for a Transmitter model using this command, use the commands listed in the Related Commands list above and Graphics (Comm) command to further define the transmitter.

At least one <Parameters> must be entered for each Comm Define command.

{ModelType} <Parameters> Description
Simple FluxDensity <Value> The value is entered in dBW/m**2, and must be between -1000.0 and 1000.0
EIRP <Value> The value is entered in Scenario Power units, and must be between -2890.0 and 2890.0 dBw
Medium FluxDensity <Value> The value is entered in dBW/m**2, and must be between -1000.0 and 1000.0
Gain <Value> The value must be between -2890.0 and 2890.0 dB
Power <Value> The value is entered in Scenario Power units, and must be between -2890.0 and 2890.0 dBw
ConstantPower {On | Off} Specify On to over-ride the power back-off computation and maintain a constant output power.
Complex FluxDensity <Value> The value is entered in dBW/m**2, and must be between -1000.0 and 1000.0
Power <Value> The value is entered in Scenario Power units, and must be between -2890.0 and 2890.0 dBw
ConstantPower {On | Off} Specify On to over-ride the power back-off computation and maintain a constant output power.

Example

For a source transmitter, to add an active beam with a frequency of 16.0 GHz and a saturate output power of 13.01 dBW to a multibeam antenna model for the Downlink antenna:

Comm */Satellite/GEO/Transmitter/Downlink Define XmtrModel Source MultiBeam Add Beam004 Frequency 16.0 Power 13.01 Active Yes

For a retransmitter, to set the basic properties of the DownlinkXmtr so that the medium model is used with a saturation flux density of -90.0, a gain of 30 dBi and a saturate output power of 13.01 dBW:

Comm */Satellite/GEO/Transmitter/DownlinkXmtr Define XmtrModel Retrans Medium FluxDensity -90.0 Gain 30 Power 13.01

For a complex transmitter, to set the basic properties of the radio_tx so that the complex model is used with a frequency of 30.0, and a saturate output power of 100 dBW:

Comm */Facility/Base_1/Transmitter/radio_tx Define XmtrModel Source Complex Frequency 30 Power 100

ReturnMessage

If activated, Connect returns an acknowledgement message.

Group Membership

This command belongs to the following group(s):

Comm

Deprecated Commands

Version

9.0

STK Programming Interface 11.0.1