Communication by the Modbus RTU
protocol with AMiT
IO modules of the DMM
series. See Communication with the IO modues by the AMiT company
This preconfiguration can be activated when creating a new object (e.g. by "New object"
in the local object menu or by pressing the Insert
key after selecting the object) and is included in the group: " / Communications / Modbus protocol"
This preconfiguration can be used with the objects: PmFolder or PmRoot.
The preconfiguration creates the PmComm
communication object and data for the corresponding number of analog and digital inputs and outputs. Also the panel with complex graphic items is created for displaying their status. This allows to define the required number for the specific connected device.
The preconfiguration is created for serial Modbus RTU
communication. The modules use the RS485
bus for the communication. It is important to ensure that additional communication parameters are correctly configured (device address, port number, bit speed, parity, ...) The configuration procedure of the devices is described in the documentation provided by the manufacturer. The communication parameters of the PROMOTIC application are defined in Settings of the serial link parameters
of the PmComm
object and in Parameters
of the PmCommData
- The preconfiguration is created including the panel (PmPanel
object) functionality as a WEB panel
- The panel is used for communication testing and it is not essential for the functionality.
In the PmComm
object named Comm
the communication parameters (Serial port
, ....) are set. The PmCommData
object named Data
includes a Parameters
page where Special Parameters
(See: PmModbusMr - Driver for communication by Modbus Master protocol
) are defined. On the Data
page, the items are imported by the data extensions of the items defined in the PmData
object (See: ExtComm
). Each Data
corresponds to the selected device type by its structure and name.
Some types of the I/O modules (DMM-DI24
) allow to use any of the binary inputs as counters. In this mode it is possible to read the walues but also write (reset the counter). Detailed specification and limitation is described in the documentation suppiled by the manufacturer.
This preconfiguration is not designed for modules of the DMM-FCx
type. These devices allow only read/write to the specific addresses in the Modbus communication that has specific meaning.
These configurators can be set before the preconfiguration is created:
|The name of created object||Name of the object created in the application object tree. This is a system name and must not contain empty string, diacritics, spaces and the first character must not be a number.|
|Serial port||Selection of the communication serial port.|
After this preconfiguration is created, the configurator is se to: PmComm > Settings of the serial link parameters > Serial port.
- The object is not connected to any port at the start of the application and the serial port can be selected dynamically by the algorithm (by the PmComm.OpenPort
- The object is meant for the data transfer over the dialed phone line (over the PmModem
object). The serial port is assigned by the PmModem.SetPmComm
method or by the PmComm object
configurator of the PmModem
- The specified serial port is opened at the start of the application. This port must be correctly configured and accessible in the OS Windows
(no one can use it).
For serial link each PmComm object must have defined another communication port. For example, when one PmComm object communicates through COM1, then next PmComm object can communicate for example through COM2 (COM3,..) but it mustn't communicate through COM1.
|Baud rate||Selection of the baud rate (bps, bit per second). |
This configurator sets the initial value of the property BaudRate.
After this preconfiguration is created, the configurator is se to: PmComm > Settings of the serial link parameters > Baud rate
|I/O module address||Valid device address within the MODBUS network. |
After this preconfiguration is created, the configurator is se to: PmCommData > Parameters > Special Parameters > Default PLC address
|Communication refresh rate [ms]||The time period in milliseconds to be used for reading the data by the PROMOTIC application. After this preconfiguration is created, the configurator is se to: PmCommData > Parameters > Communication refresh rate [ms]|
|The number of analog inputs||Possible to enter the number according to the device type|
|The number of digital inputs||Possible to enter the number according to the device type|
|The number of digital inputs used as counters||Possible to enter the number according to the device type|
|The number of digital outputs||Possible to enter the number according to the device type|