Canoe: the difference between environment variables and system variables

Problem description ：CANoe In simulation , How to distinguish between environment variables and system variables .

The problem background ： Realization XVehicle Simulation and CAN Two projects of bus simulation , Environment variables and system variables are used respectively , Perform panel control and CAPL Programming . Its usage is very similar , Can be bound to panel Control , Can also be used in CAPL Listening in programming 、 Perform corresponding functions . So what is the difference between the two ？ It can't be seen from the simulation example value , The explanation in the book is also very vague . So there is this question .

Come to the conclusion first ： There is no difference in function , Are equivalent to global variables , Facilitate software data interaction ; Use system variables first .

Here's why ：

1. stay V6.0 The old version before CANoe in , use environment variable Transmit data during software simulation .

2. from CANoe V6.0 Start , use System variables As a way to transmit data in simulation environment independent of specific bus . Decouple the relationship between bus type and variable configuration .

stay CANoe V6.0 after , Not only simulation CAN The Internet , And support LIN、FlexRay And other types of bus simulation .

Environment variables are generally passed DBC Definition , but DBC Generally only used for CAN The Internet .

In Africa CAN Network configuration Engineering , You also need to add extra DBC Specifically used to store environment variables .

For the unified management of variables , Introduce system variables , System variables are stored in CANoe Configuration Engineering (cfg file ） in , This means that system variables are independent of any bus and its database .

3. from CANoe V12.0 after , Environment variables are no longer supported .（ For your own use CAN12.0Demo edition , Environment variables are still supported ）

difference

At a stage where both can be used , It can be done through the following points distinguish :

	sysvar（ priority of use ）	envvar
Support bus type	Any bus type	only CAN Bus
Simulation meaning	Node internal parameters (CAPL Program )	Node I/O The signal （ Panel or real I/O）
Define the location	Environment window -SysVar	DBC
Save the location	CANoe Configuration Engineering (cfg file ）、 Independent external XML	dbc file
data type	There are arrays , Yes 32 Wei Wu / signed int	No array , nothing 32 Bit unsigned integer
Read and write functions	SysGetVariableInt/SysGetVariableFloat/ SysSetVariableInt/SysSetVariableFloat	putValue/getValue

For more detailed instructions , You can refer to the following two articles , It's very clear ：

1. source , Cause difference ：Vector Tools CANoe/CANalyzer The basic difference between environment variables and system variables - You know

2. Differences in use ：CANoe Operation introduction series ———— System variables and environment variables _ Forever Caiji Xiaozhan's blog -CSDN Blog _canoe System variables and environment variables 3. In depth understanding of CANoe System variables in （System Variables）_ The car Internet thing -CSDN Blog _canoe System variables  

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