Unit (Communication driver)

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Unit (Communication driver)

Unit (communication driver)

In the world of FA-Server, communication drivers for connecting to PLC and other devices are called "units."

 

(Example of unit definition)

p_tag_0010

 

By defining a unit in FA-Server, it is possible to connect to downstream devices such as PLC or remote I/O, or to tags from other FA-Server, or to connect to OPC servers made by other companies.

 

When creating a tag, first register the unit under Tag/Driver in the left tree of FA-Server. Then create a "folder" under the registered unit, and create the tag under the folder. Roughly speaking, the relationship between units and tags can be thought of as a unit of PLC, and a tag as a single device address.

 

Furthermore, multiple units can be defined at the same time. In other words, it is possible to connect to multiple PLCs at the same time, making it easy to build a SCADA system that contains a mixture of different PLC models from different manufacturers.

 

 

Unit Classification

The units are broadly divided into three types:

 

content

overview

PLC unit

 

This is a unit for communicating with PLC. It comes with built-in communication functions for 100 types of PLCs as standard, and you can select the target PLC from the driver list and register it as a unit.

 

Memory Unit

 

In addition to units that connect to PLC, you can register virtual units that are deployed only in the memory space of FA-Server. These units can be used to hold tag values on FA-Server, or to use them as shared memory to share information between multiple FA-Server.

 

There are two types of units that are expanded only in memory:

 

Connection method etc.

explanation

Virtual Device

A virtual device is a device that uses the memory address space on FA-Server and is a unit that simulates the address map (M, D, etc.) of PLC. It can also be used as a shared area when you want to share data between multiple temporary clients.However, data is not retained for virtual devices. Therefore, if you restart the Server application or switch the Server duplex, the data will return to the initial value.

 

Memory Device

Memory devices are devices that use the memory address space on FA-Server. They come with useful functions such as a time bit tag (setting the current time as the tag value), a pulse bit tag (setting the tag to automatically OFF a certain amount of time after turning ON), and a survival confirmation tag (setting to determine an abnormality if no writing is done for a certain amount of time).With memory devices, you can save tag values on the PC's hard disk by setting "Save values" in the unit's communication settings.If you want to retain system settings, please consider using a memory device.

 

 

External Collaboration Unit

 

There are units available for connecting to the outside world via a network. For example, by registering the "OPC" unit, you can connect to tags on a third-party OPC server. Or, by using the "IPLink" unit, you can link tags from multiple FA-Server. There are also units available for connecting to a database via tags via the ODBC driver, or to cell data in Excel via tags.