Connection to AMiT station via AMiT DB-Net protocol

Patron Neuron Gate Unipi 1.1 Axon

Mervis also allows connection via AMiT DB-NET protocol, thus it is possible to connect any AMiT device with ETH interface to Unipi controller and revitalize the whole system (visualization, remote access, SCADA, etc.) without complicate HW modifications. The connection is relatively easy, fast and can be done even by a less experienced Mervis IDE user.

First it is necessary to set up the AMiT PLC (slave) and generate the definitions HW.ini and DB.ini. Mervis IDE imports both files together, so they must be in the same directory.

To create a new communication channel, right-click on the PLC and select “Add Channel”:

Highlight the newly created channel by mouse click, in the right column select “Protocol: AMiT DB-Net” and set the “AMiT DB-Net protocol parameters” so that the parameters do not conflict with another device on the AMiT DB-Net network:

If the goal is only to read data from AMiT and not to write it, the following section “Modification” can be skipped and continue with import into solution.

To enable writing from Unipi to AMiT, you must first modify the DB.ini file. To edit, open the file in a text editor (e.g. Notepad++ or Sublime) and add the first line:

!Name,wid,type,stationnumber,writable,explode,note

Next, it is necessary to add two more columns in the data between the device address (stationnumber) and the name (note):

1. The first one, marked “writable”, allows to set (0/1) in the definition that it is a data point for writing
2. The second column “explode” allows to split (in the case of a matrix) into several individual data points (instead of an array). This is useful when working in FBD rather than ST, as arrays are very difficult to use in FBD. To split the matrix into individual data points, set the value in the column to 1.

It is possible to define the device manually, but this is time-consuming, difficult and error-prone. It is also possible to add a device from a library, but this is not suitable in this case as each device (installation) is unique. Therefore, it is most suitable to import a definition that has been exported directly from a running AMiT station.

Right-click on the AMiT_DB-Net communication channel and select “Import Device Definition”:

In the dialog open the directory with the HW.ini and DB.ini files (or DB.ext.ini), select the HW.ini file and start the import by clicking “Open”:

When the import is complete, one or more devices are created within the communication channel:

The AMiT DB-Net device parameters (device address on the AMiT network & device password) and UDP parameters (device address - IP/URL & device port - UDP) must now be set in the properties of each added device.

Once completed, it is recommended to double check all properties and data points within the device for correctness and then upload the solution. If all parameters are correct, the devices will communicate immediately after uploading the solution, which can be verified in the system status during debugging.