Source code documentation

1. Project description

The Continuous Measurement and Logging (CML) Delacor Queued Message Handler (DQMH) sample project is a variation of the NI QMH based CML project using DQMH® modules instead of separate Message Handle Loops.

2. My Computer

2.1. DQMH® modules

This section describes DQMH® module responsibilities and relationships.

2.1.1. Preamble

A DQMH module is the main component of an architecture based on DQMH® framework. A DQMH module is used to implement a section of the application that has one responsibility.

DQMH® framework defines two different type of DQMH module.

Singleton:

A Singleton DQMH module can have only one instance running at any given time.

Cloneable:

A Cloneable DQMH module can have one or multiple instances running in parallel.

DQMH® framework defines two different ways to carry data throughout the application and with both other DQMH modules and non-DQMH based code.

Request events:

A request is a code that fires an event requesting the DQMH module to do something. Multiple locations in the code can send events to the DQMH module.

Request events are many-to-one.

Requests are usually named using imperative tense.

Broadcast events:

A broadcast is a code that fires an event broadcasting that the DQMH module did something. Multiple Event Structures can register to handle the Broadcast Events.

Broadcast Events are one-to-many.

Broadcasts are usually named using past tense or passive voice.

Note	Refer to the DQMH® framework official documentation to find more details on how the framework works

The following section gives you details on the project architecture relying on this framework. It gives you an overview of the modules' interaction and detailed information on each module.

Graphs used in this section have the following legend:

Components:

Events:

Start and Stop module callers:

2.1.2. Modules overview

This project contains the following modules.

Table 1. Modules list
Singleton	Cloneable
CML UI.lvlib
Acquisition.lvlib
Logger.lvlib
Settings Editor.lvlib

This graph represents the links between all DQMH modules.

2.1.3. CML UI.lvlib

Type: Singleton

Responsibility: This module is the user interface of the Continuous Measurement and Logging application.

Module Start/Stop calls

Table 2. Start and Stop module callers
Function	Callers
CML UI.lvlib:Start Module.vi	CML Main.vi Test CML UI API.vi
CML UI.lvlib:Stop Module.vi	CML UI.lvlib:Handle Exit.vi CML Main.vi Test CML UI API.vi

Module relationship

Table 3. Requests callers
Request Name	Callers
CML UI.lvlib:Show Panel.vi	CML Main.vi Test CML UI API.vi
CML UI.lvlib:Hide Panel.vi	Test CML UI API.vi
CML UI.lvlib:Get Module Execution Status.vi	CML UI.lvlib:Start Module.vi CML UI.lvlib:Obtain Broadcast Events for Registration.vi
CML UI.lvlib:Show Diagram.vi	Test CML UI API.vi

Table 4. Broadcasts Listeners
Broadcast Name	Listeners
CML UI.lvlib:Module Did Init.vi	Test CML UI API.vi CML Main.vi
CML UI.lvlib:Status Updated.vi	Test CML UI API.vi CML Main.vi
CML UI.lvlib:Error Reported.vi	Test CML UI API.vi CML Main.vi
CML UI.lvlib:Module Did Stop.vi	Test CML UI API.vi CML Main.vi
CML UI.lvlib:Update Module Execution Status.vi	Test CML UI API.vi CML Main.vi

Table 5. Used requests
Module	Broadcasts
CML UI.lvlib	CML UI.lvlib:Get Module Execution Status.vi
Acquisition.lvlib	Acquisition.lvlib:Stop Acquiring.vi Acquisition.lvlib:Calibrate DAQ.vi Acquisition.lvlib:Start Acquiring.vi
Logger.lvlib	Logger.lvlib:Initialize File.vi Logger.lvlib:Stop Logging.vi
Settings Editor.lvlib	Settings Editor.lvlib:Show Panel.vi

Table 6. Registered broadcast
Module	Broadcasts
<<>>
Acquisition.lvlib	Acquisition Started.vi Acquisition Stopped.vi Data Updated.vi Device Calibrated.vi Error Reported.vi Module Did Init.vi Status Updated.vi Update Module Execution Status.vi
Logger.lvlib	Error Reported.vi Module Did Init.vi Status Updated.vi Update Module Execution Status.vi
Settings Editor.lvlib	Error Reported.vi Module Did Init.vi Status Updated.vi

Module custom errors

Tip	Custom errors are added to the module via vi named `*--error.vi`.

Module CML UI.lvlib use the following custom errors:

Table 7. Custom errors
Name	Code	Description
Module Not Running	403681	%s Module is not running.
Module Not Stopped	403682	The Stop Module VI for the %s module timed out while waiting for the module main VI to stop. The module main VI may still be running.
Module Not Synced	403683	%s Module was unable to synchronize events.

CML UI.lvlib:Start Module.vi

Event type: Not a DQMH Event

Description:

Launches the Module Main.vi. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Stop Module.vi

Event type: Not a DQMH Event

Description:

Send the Stop request to the Module's Main.vi. If Wait for Module to Stop? is TRUE, this VI will wait until the module main VI stops, and will timeout at the Timeout to Wait for Stop value. This value defaults to "-1", which means the VI will not timeout, and will always wait until the module main VI stops before completing execution. Note: The Timeout to Wait for Stop value is ignored if 'Wait for Module to Stop?' is set to FALSE. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Show Panel.vi

Event type: Request

Description:

Send the Show Panel request to the Module's Main.vi. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Hide Panel.vi

Event type: Request

Description:

Send the Hide Panel request to the Module's Main.vi. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Get Module Execution Status.vi

Event type: Request

Description:

Fire the Get Module Execution Status request. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Show Diagram.vi

Event type: Request

Description:

This VI tells the Module to show its block diagram to facilitate troubleshooting (add probes, breakpoints, highlight execution, etc). _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Module Did Init.vi

Event type: Broadcast

Description:

Send the Module Did Init event to any VI registered to listen to this module's broadcast events. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Status Updated.vi

Event type: Broadcast

Description:

Send the Status Updated event to any VI registered to listen to events from the owning module. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Error Reported.vi

Event type: Broadcast

Description:

Send the Error Reported event to any VI registered to listen to events from the owning module. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Module Did Stop.vi

Event type: Broadcast

Description:

Send the Module Did Stop event to any VI registered to listen to this module's broadcast events. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

CML UI.lvlib:Update Module Execution Status.vi

Event type: Broadcast

Description:

Broadcast event to specify whether or not the module is running. _____ Based on Delacor QMH Project Template 4.0.0.47. _____ Based on Delacor QMH Project Template 4.2.1.64.

2.1.4. Acquisition.lvlib

Type: Singleton

Responsibility: This module handle the continuous data acquisition.