Configuration of PROFINET Shared Device Functionality

PROFINET Shared Device Functionality enables an IO device to be connected to more than one IO controller at the same time. In this situation the IO controllers share the IO devices IO modules/submodules to have access to the IO data. Each IO controller exclusively connects a set of IO modules/submodules as defined in its configuration. Accessing the same IO device modules/submodules by more than one IO controller in parallel is not allowed for Shared Device.

Following picture taken from PROFINET IO System Description as provided by PNO gives an impression about the concept of Shared Device Functionality.

Each IO controller that should connect the shared IO device has to have this device configured in its device list. In ABB Automation Builder all configurations of the shared IO device have to look the same at all IO controllers; all modules/submodules have to be configured in the same order. Each IO controller has to be configured which modules/submodules should be connected.

One of the IO controllers has to be defined as responsible to connect the IO device access point (DAP) with its assigned submodules. To do so Automation Builder provides the parameter Shared Device. This parameter can be found in the IO device configuration as part of the device list sub-tree of the IO controller. Parameter Shared Device defines which IO controller will connect the DAP and which IO controllers use the IO device just as shared device.

To connect the DAP this parameter must not be checked; at all other IO controllers this parameter has to be checked.

If this rule is not followed accurately the PROFINET communication will start anyway but the IO controllers / IO devices may signal errors.

Two possible error cases have to be considered:

Error Case 1	Effect
All IO controllers have parameter Shared Device selected. Thus, no IO controller will connect the DAP to load related parameters.	No error will be signaled; PROFINET network will run with default parameters.

Error Case 2	Effect
More than one IO controller has parameter Shared Device unselected. These IO controllers try to connect to the DAP in parallel.	One IO controller will succeed. The other IO controllers will fail but further modules/submodules can be connected with success. Communication will run to connected modules/submodules. The IO device responds with error signaling DAP’s submodules as already connected.

In Error case 2 IO controller and IO device specific diagnosis pages in Automation Builder, will show error information. See CM579-PNIO: IO \ Controller ViewsCM579-PNIO: CM579-PNIO PROFINET IO Device Views

In display CM579-PNIOPROFINET IO Device Views field Diagnosis state shows a text message describing the error. Basically this text depends on the type of device signaling the error. In case of CM589-PNIO-4 the text The IO-Device reported a ModuleDiffBlock during connection establishment will be found.

Note

Take care to have parameter Shared Device unselected at one IO controller device and have it selected at all other involved IO controller devices.

This rule also applies in case of using different Automation Builder projects or 3:sup:rd party IO controller devices.

The following workflow applies to configure an IO device to be connected by more than one IO controller as shared device:

• Add IO device at first IO controller
• Add list of IO modules as defined at IO device configuration itself
• Define set of IO modules to be connected by this IO controller
  • use function connect/disconnect
• Add same IO device the same way at further IO controllers
• Define set of IO modules to be connected for each of the further IO controllers
• Define one IO controller to be responsible to connect DAP
  • this may be a different IO controller outside this configuration
  • parameter Shared Device in Automation Builder; may be different approach at 3^rd party tools

Inserting an IO module at a PROFINET IO device assigned to a CM579 IO controller defines this module as to be connected by default. If the module should not be connected by this IO controller this setting has to be adjusted. Via context menu at IO device module sub-tree Automation Builder provides the function disconnect module to define a certain module as not to be connected.

To define a not connected module as to be connected again the context menu shows the function connect module.

The module nodes that are configured to be connected will be shown in active state (black style). Modules not to be connected will be shown in in-active state (gray style).

Once a PROFINET IO device is configured as child at an IO controller the IO device sub-tree (complete IO device or its module configuration) may be copied from one IO controller node to a different. The selection which modules should be connected has to be adjusted to the needs at the new position.

The following example shows a configuration of Shared Device usage by using one AC500 CM589-PNIO-4 IO device and two IO controllers represented by two ABB CM579-PNIO IO controller modules.

CM579_PNIO_1 connects the modules InputBy_1 and InputBy_2 only; represented by CM589 PNIO_Device modules DevInputBy_1 and DevInputBy_2.

CM579_PNIO_2 connects module InputWrd_1; represented by PNIO_Device modules DevInputWrd_1.

The other modules are not connected here but may be connected from outside this configuration by an external IO controller.

In case of connecting the same module/submodule by more than one IO controller only the first connect will have success. All further connect attempts will fail. The IO device will reply to those attempts with a connect error. The effected IO controllers will show this error at their diagnosis interface.

Note

See PLC-Diagnosis: IO \ Controller Views

In display CM579-PNIOPROFINET IO Device Views field Diagnosis state shows a text message describing the error. Basically this text depends on the type of device signaling the error. In case of CM589-PNIO-4 the text The IO-Device reported a ModuleDiffBlock during connection establishment will be found.

Note

Rules to be followed on using PROFINETShared Device configurations:

• All configurations of the IO device at IO controllers using this IO device have to look the same
• IP configuration (IP address, subnet mask) have to be the same
• Station name has to be the same
• Configure each IO module as to be connected at one single IO controller only
• Automation Builder is not able to check these details for consistency

Note

In case of using more than one single IO controller device in the same network take care to assign unique station names and IP addresses to these IO controller devices.

Note

In case of having a configuration with overlapping module usage it cannot be foreseen which IO controller will connect to which module. The result of connecting the modules/submodules depends on the start-up sequence of the complete system. The IO controller running first will get the connection.