MSMQ

MSMQ (Microsoft Message Queuing) is a Windows-based messaging infrastructure that enables different applications and computers to communicate with each other through messages.

In traditional application communication, the sending application attempts to connect directly to the receiving application to deliver data. With the MSMQ approach, the sender places the message in a queue instead of sending it directly to the application. The receiving application can then read the message from the queue.

This eliminates the requirement for both applications to be running at the same time. Even if the receiving application is temporarily unavailable, the message can remain in the queue and be processed when the application starts again.

In Microsoft's documentation, MSMQ is described as a messaging service that provides features such as asynchronous and reliable messaging, persistent message storage in queues, routing, security, and prioritization.

The easiest way to understand how MSMQ works is to think of a mailbox. The sending application places a message in the queue. The message is stored by the queue, and the receiving application retrieves it when it is ready.

One of the fundamental components of the MSMQ architecture is the Queue Manager. The Queue Manager is responsible for managing message queues on the computer and for operations related to sending, receiving, and processing messages.

When an application wants to send or receive messages using MSMQ, it communicates with the Queue Manager. The Queue Manager also plays a role in transferring messages between Queue Manager components running on different computers.

In MSMQ, a message is a unit of information sent from one application to another. A message can contain data defined by the application as well as properties related to how the message is delivered and processed.

For example, in an industrial application, the message content may include an alarm notification, device status, measurement value, operator command, or event record.

How the message content is interpreted is determined by the sending and receiving applications. Therefore, MSMQ is not an industrial data model that defines what a message means from an application perspective.

The appropriate queue type is determined according to the application's architecture, network environment, and security requirements.

One of the important advantages of MSMQ is that it can decouple communication between applications from direct connections. After placing a message in the queue, the sending application does not have to wait for the receiving application to respond immediately.

This approach can be particularly useful in situations involving temporary network interruptions, application restarts, or systems that need to communicate while operating at different speeds.

For example, a fast data collection application can transfer data to a slower recording or analysis application through a message queue without requiring a direct connection between them.

Rather than thinking of MSMQ as a single network protocol, it is more accurate to consider it a protocol family used by the Message Queuing service.

Microsoft's MSMQ protocol documentation defines various protocols for different purposes, including message transfer, communication between the Queue Manager and clients, management, remote queue reading, and directory services.

• Queue Manager Client Protocol
• Binary Reliable Messaging Protocol
• SOAP Reliable Messaging Protocol (SRMP)
• Queue Manager Management Protocol
• Queue Manager Remote Read Protocol
• Directory Service protocols

This architecture enables MSMQ to support not only queue operations within applications, but also message transfer and management operations between Queue Manager components running on different computers.

MSMQ can use different communication mechanisms. Traditional MSMQ message transfer can use TCP/IP and UDP-based communication. Microsoft's Windows Server network requirements documentation lists TCP/UDP 1801 among the main service ports used by MSMQ.

SRMP (SOAP Reliable Messaging Protocol), MSMQ's HTTP-based communication mechanism, can transfer SOAP messages over HTTP or HTTPS.

HTTP/HTTPS-based communication provides an alternative that can be used especially in communication scenarios across different networks.

MSMQ is not a communication protocol for PLCs or field devices. Instead, it can be used by industrial software applications to exchange data and events reliably with each other.

For example, instead of sending data collected from field devices directly to another application, a SCADA system can place the data into an MSMQ queue. Data processing, reporting, archiving, or analysis applications can then read these messages from the queue.

Although both MSMQ and MQTT can be used for messaging, they are not the same technology.

Therefore, in SCADA or industrial software architectures, MSMQ and MQTT do not necessarily have to be direct alternatives to each other. Depending on the use case, both technologies can also be used for different purposes within the same system.

• Enables asynchronous communication between applications.
• Sending and receiving applications do not have to be running at the same time.
• Messages can be stored in queues.
• Provides a communication model suitable for distributed applications.
• Provides message prioritization capabilities.
• Can be used together with the Windows security infrastructure.
• Can be integrated with Windows services and .NET applications.
• Can transfer data, event, and command messages between industrial software applications.

Although MSMQ is a powerful messaging infrastructure, it is not necessarily the most suitable technology for every application. When designing a new system, factors such as the operating system, application architecture, network environment, security, and interoperability requirements should be considered.

MSMQ can be a meaningful option, particularly in environments with a large number of Windows-based applications. On the other hand, for projects requiring support for different operating systems, IoT devices, or a wide range of platforms, MQTT, AMQP, or other modern messaging technologies may be more appropriate.

In addition, when implementing a message queuing system, issues such as queue growth, messages that cannot be consumed, network failures, authorization, and error handling should be addressed separately in the application design.

MSMQ (Microsoft Message Queuing) is a message queuing technology developed to provide reliable and asynchronous messaging between applications in Windows environments.

The basic idea is simple: One application places a message in a queue, the message is stored there, and another application reads and processes it when it is ready.

This architecture enables communication between SCADA, Data Logger, Event Recorder, reporting, data analysis, and other industrial software components without requiring direct connections between them.

Particularly in Windows-based distributed industrial software architectures, MSMQ can be considered a reliable messaging layer between applications.

This section will provide tools that can be used to work with MSMQ, manage queues, send and receive messages, test connections, and develop MSMQ-based applications.

MSMQ tools that will be developed or shared as part of the EOS Industrial Software Portal will be added to this section over time.

You can contact us about MSMQ, industrial software, or technical content.

• benanbasoglu@gmail.com
• ANKARA