FBM214 P0922VT Foxoboro communication input interface module

Description

The FBM214 serves as a HART communications field device host, enabling the I/A Series system to request and receive two digital messages per second from the field device. The message pass-through capability can be used to support HART universal, common practice, and device-specific commands, but not the burst communication mode. These commands are implemented using the Intelligent Field Device Configurator (IFDC — refer to PSS 21S-8A3 B3 for details).

The FBM214 provides a common isolated power supply to power all eight channels. Optionally, the channels can be powered by an external power supply. However, when a common external power supply is used with two or more channels, a Cable Balun module is required to prevent channel cross talk.

The advantages of reusability and easy management in computer object-oriented programming include reusability and easy management, which have also been discussed in PLC. Taking Step7 as an example, it is necessary to discuss the differences between FC and FB. Observing the data type, FB only has one more “STAT” type than FC. In terms of usage, FB requires a background DB, while FC does not. However, this difference results in FB having its own independent data storage space, while FC’s data storage must rely on public variables (such as intermediate variable M or shared DB).

There is a criterion that the stronger the independence of the program block, the better its reusability, and the less likely it is to generate data access conflicts, It is easier to manage. Some companies produce PLCs with programming languages that do not have FB like features. In this case, an alternative solution similar to “FC+Shared DB” can be adopted, but its independence has been greatly reduced. The independence of the same code is an important aspect of standard development, and it is difficult to imagine that a functional block with countless connections with other functional blocks can be effectively reused as a standard block in different projects. Throughout the development of computer languages, the initial programming was terrifying, but today’s programming provides great relief for people.

There are many ready-made standard libraries that are practical, and people can focus more on implementing the functions themselves. PLC programming should also develop in this direction, allowing more people to engage in application level design, and those standard function blocks should not be repeatedly developed by different personnel, Although major PLC factories have developed a large number of program libraries, industrial control objects are diverse, and different industries should have their own program libraries. The reusability of code is the key to evaluating the quality of these functional blocks.

Progressiveness of design idea In the circuit diagram design, we have already used the drawing method for the control object, that is, after the basic main distribution circuit and PLC are configured, we will draw the circuit diagram for each field control object, such as motor, valve, cylinder and other control objects. Their power comes from the main distribution circuit, and the control and feedback are connected with the PLC. The hardware interlock is adjusted according to the actual situation, Control objects are organized and stacked like building blocks. Similarly, programming is achieved by using corresponding standard control blocks for each control object, effectively encapsulating program control details, making the program look simple and easy to maintain. Good design can effectively associate schematic diagrams with the program, even achieving one-on-one relationships, As shown in the schematic diagram, a control object can be found in the program to correspond to the corresponding FB call.