Software Toolbox Technical Blog

The DNP3 protocol is commonly used in water/wastewater and other utilities related industries. It's common for RTUs used in these industries to support both DNP3 and Modbus (and possibly other communications protocols). DNP3 has many features compared to Modbus (and other more traditional protocols) that make it desirable for such remote telemetry applications including buffered event history and unsolicited (or Report-By-Exception).

But if you're new to working with DNP3 (it's common for users in such industries to be quite familiar with Modbus but not so familiar with the quirks of DNP3), it's important to understand how differently it behaves with respect to polling frequency, polling composition and considerations when configuring the DNP3 outstation/device itself.

Continuing our Tech Support Corner blog series, this post discusses what drives the polling behavior for DNP3 drivers in TOP Server and how the configuration on the device itself can impact what data is returned when a poll is issued.

This week's post is a technical update to share news about updates released for DataHub and OPC Data Logger, reminders about the value of the Tech Support corner, and your last warning about DCOM Hardening before the Windows update next week!

The team is working on some more tech tips and video tutorials that you'll start seeing later this month. Meanwhile, here's this week's update.

With Modbus having been around since 1979, I’m sure you have had some interaction with it or at least awareness of it if you work in the automation industry. Our TOP Server is very widely used for its Modbus TCP/IP Ethernet Driver and variety of Modbus serial drivers to enable users to connect to any Modbus devices that they have in the field. For that common use case, the device is the Modbus Server, and the TOP Server is the Modbus Client.

But what if you needed to configure TOP Server to be the Modbus TCP/IP Server (i.e. the “device”)? That is the purpose of this next post in our continuing Tech Support Corner blog series – to discuss and tell you how you can configure TOP Server to act as a Modbus server device, which is a common need for systems where either a device or other software application can only act as a Modbus Client and you have other systems that need connectivity to that Modbus client.

A common misconception about TOP Server as an OPC server is that TOP Server will poll your device/devices automatically with no OPC client connected. So, when you are getting started with TOP Server, it is good to have an accurate understanding of how interactions occur between each node of a basic OPC architecture— client-server and server-device— to ensure that the configuration meets your needs and can be scalable to more demanding projects.

Continuing our Tech Support Corner blog series, in this blog post, we will discuss some basics of the interactions between an OPC client and server, including different types of reads and the expected behavior that you'll see as a result of those interactions.

If you're a TOP Server user with OPC UA client connections to TOP Server, you may have noticed a section in the OPC UA Configuration Manager titled "Discovery Servers". Possibly you're using an OPC UA Local Discovery Server (LDS) but many of our users aren't sure what an LDS is, how to use one with TOP Server or why they should.

Continuing our Tech Support Corner blog series, in this blog post, I will step through how to make TOP Server discoverable via a Local Discovery Server or a Global Discovery Server using the OPC UA Configuration Manager, as well as what this does behind the scenes so that you can make other OPC UA servers discoverable even if they don’t have a similar built-in configuration tool.

Users of AVEVA™ software are already familiar with the native connectivity options they have for interfacing with different systems and devices. AVEVA users often turn to Cogent DataHub® for integration of a wide variety of industrial and other data sources such as MQTT clients/brokers, SparkplugB systems, databases, historians and much more.

AVEVA InTouch users have traditionally connected to DataHub via its OPC DA Classic interface (via AVEVA OI Gateway). AVEVA's OI Gateway also provides those users the additional option of connecting to OPC UA data sources, for easier and more secure remote connections to such data sources.

In this video blog post, we will cover the basic steps to connect AVEVA InTouch to DataHub via OPC UA, expanding the variety of connectivity options available to AVEVA users.

Most AVEVA™ users are already familiar with the native connectivity options they have for interfacing with different systems. AVEVA users have turned to OmniServer for many years to integrate non-PLC devices such as barcode scanners, weigh scales, vibration monitors, RFID readers and more, all without custom code.

Those users of AVEVA InTouch have traditionally connected to OmniServer directly via its native SuiteLink interface. AVEVA's OI Gateway provides those users the additional option of connecting to OPC UA data sources, for easier and more secure remote connections to such data sources.

In this video blog post, we will cover the basic steps to connect AVEVA InTouch to OmniServer via OPC UA, expanding non-PLC device connectivity options for AVEVA users.

Most AVEVA™ users are already familiar with the native connectivity options they have for interfacing with different systems. Many AVEVA users have also turned to TOP Server over the years, both for standardizing device connectivity in a single server and for drivers/protocols not available as native AVEVA options as a complementary solution.

Those users of AVEVA System Platform have traditionally connected to TOP Server directly via either its native SuiteLink interface. AVEVA's OI Gateway provides those users the additional option of connecting to OPC UA data sources, for easier and more secure remote connections to such data sources.

In this video blog post, we will cover the basic steps to connect AVEVA InTouch to TOP Server via OPC UA, expanding device connectivity options for AVEVA users.