MxVDev and MxTransIt each have their own Signal Dictionary. To access the MxVDev Signal Dictionary, select Project‑>Signal Dictionary from the main menu. See Using the Signal Dictionary.

Often when starting a new project the first thing to be established is the Signal Dictionary.  It itemizes and describes the input and output Signals of a system. It is important to get the definition of these Signals correct early in the project, and it is not always as straight forward as might be imagined, especially when one is considering test portability.

It is useful to have a good naming convention.  With a well-defined naming convention, a shorter name can convey a lot of information about the Signal.  Projects may have hundreds (even thousands) of signals defined.  It is important to be able to identify the correct signal.

Here are some guidelines for naming:

•Signals should be described and named in terms of their meaning and not an implementation.  For example:

oIf a heated seat can be commanded to be set to Off, Low or High, two ways to name the input to the heated seat controller are:

▪HeatedSeatRockerSwitch, with positions Up, Down, Center

▪HeatedSeatCommand, with values: HS_Off, HS_Low and HS_High

oThe second option is a better choice for several reasons:

▪The switch can be swapped out for a rotary switch and the test will not change.

▪The enumeration labels are more descriptive.

▪If testing a model, it is unlikely that there would be implementation details in the model.

•If testing software, don't include the C variable type in the name string (this is not portable to MIL or HIL).

•If using an I/O card, avoid any reference to the I/O pins of the card (unless it the I/O card that you are testing.

•Group enumeration labels by using a common prefix (for example, Wiper_Fast, Wiper_Slow, Wiper_Off)

Sources of Signal Data

There are several ways to get information about Signals into the MxVDev Signal Dictionary:

•Import from MxTransIt - See Connecting Signals

•Enter data manually - See Using the Signal Dictionary

•Import from a CSV file - See Importing Signals

•Set up the Signals in the PortDefs array (AppIF.c File) when using the MxVMC (Virtual MicroController)

•Import Enumeration Labels from a CSV file

•CAN or LIN bus signals are defined in a DBC or LDF

In MxTransIt, the Signal Dictionary is populated when ports are created.

•You can set the port properties manually using the Edit Port command.

•For some Transforms, you can also set these values in the Properties box.

•The data can also come from a Simulink model. If the properties from the Simulink model do not match the values in the Signal Dictionary, a warning is generated.

•If you are using a VMC, the port properties come from the AppIF.c file.

Related Topics:

Using the Signal Dictionary

Signal List

Signal and Port Properties