Absolute Reference (G)

(Not recommended) Reference point at zero absolute temperature and pressure

Using this block is no longer recommended. Instead, make absolute measurements by setting the Measurement reference parameter of the Pressure & Temperature Sensor (G) block to Absolute. (since R2023a)

• 

Libraries:
Simscape / Foundation Library / Gas / Elements

Description

The Absolute Reference (G) block represents an absolute reference for the pressure and temperature in a gas network. At port A, the pressure and temperature are both equal to zero.

Unlike other domains, where each topologically distinct circuit within a domain must contain at least one reference block, gas networks do not have this requirement. For more information, see Reference Node and Grounding Rules.

The purpose of the Absolute Reference (G) block is to provide a reference for the Pressure & Temperature Sensor (G). To measure the absolute pressure and absolute temperature of a node, connect that node to the A port of a Pressure & Temperature Sensor (G) block. Connect the B port of the Pressure & Temperature Sensor (G) block to an Absolute Reference (G) block.

If you use the Absolute Reference (G) block elsewhere in a gas network, it triggers a simulation assertion because gas pressure and temperature cannot be at absolute zero.

Ports

Conserving

A — Pressure and temperature are zero

gas

Gas conserving port where the pressure and temperature are both equal to zero.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2016b

R2023a: Absolute Reference (G) block no longer recommended

The Pressure & Temperature Sensor (G) block now contains an implicit reference node, which means that you need only one port to make absolute measurements of pressure or temperature. Expose the second port only if you need to measure the difference in pressure or temperature between two nodes in the model.

In previous releases, to measure the absolute pressure and absolute temperature at port A, you needed to connect port B to an Absolute Reference (G) block. This is no longer necessary because you can now make absolute measurements by setting the Measurement reference parameter of the Pressure & Temperature Sensor (G) block to Absolute.

This change has no compatibility impact. Existing models that have an Absolute Reference (G) block connected to a Pressure & Temperature Sensor (G) block continue to work as before.