Read different technical overviews on industrial data communications,
the technical solutions, that will help you, perhaps, but it will be relevant
Modbus communication protocol was developed in 1979, and over 40 years later, it is still used on many industrial sites. It is pretty cool that this openly published, free, simple protocol has been adopted by so many manufacturers to exchange information.
So, why are we still using modbus today? ...
The expression topology refers to how a network is structured; the physical or logical placement of the nodes. There are six basic topologies: point to point, ring, star, bus, combined and mesh network. The choice of topology is important, as it is a long term infrastructure that shall manage and transport important data without downtime.
Fibre optics (optical fibres) are long, thin strands of very pure glass about the diameter of a human hair. They carry much more information than conventional copper wire and one of the advantages of fibre cable is that it is completely insensitive to electromagnetic interference (EMI).
It is therefore ideal for installations in harsh industrial environments. It provides reliable transmission and high data transfer capacity over long distances. For example, almost all telephone long-distance lines (cross country) are fibre optic cables.
It’s 4 PM on Friday, when the phone rings with news that the palletizer on your plant’s main bottling line just went down.
The plant technical team is stumped and the palletizer vendor’s service engineer won’t arrive until Monday.
The plant manager is on the other end of the phone line, asking you to somehow let the vendor access the palletizer control equipment to resolve the problem remotely. Otherwise, he’ll need to idle the plant through the weekend, costing your company tens of thousands of dollars in lost revenue and wages.
The answer to this one is most certainly yes. Even though Ethernet became the “go to” technology for industrial networking at the turn of the century it is amazing how much equipment with the old RS-232 or RS-485 ports are still in use. A problem we are starting to notice is that the younger engineers are not being taught about these old favourites and many of the old hands are now retiring. With this in mind I thought an article covering some of the basics of serial communications might be helpful.