Devices are defined on the node where the device driver is installed and where the device specific communication to the physical device will take place. Physical devices types include: PLCs, controllers, sensors, and bar code readers.
In the case of logical devices, the device is defined on the node where the memory representation of the device and its variables will take place. There is no physical device to connect to and no communication protocol to support. Logical device types include: global variable device, aliases device, and property file reader device.
Once a device is defined and Started, the device's variables are available to triggers, on the same node, for read and write access. Follow these general steps to add a device definition to a node, each device type has its own specific parameters:
- From the left pane, expand the node that you want to add a device definition to.
- Click Devices.
The Devices window appears as the right pane. - From the bottom of the Devices
tab, select New.
A default Device window appears.
- In the Name box, type a name for the local device. A device name can be up to 64 characters and include letters, numbers, and the underscore character. Spaces are allowed.
- Use the Type down-arrow to select
the device type.
The available device types are determined by the support available on the node. Install the packages by going to Administration -> Packages tab.
The Device window changes to accommodate the selected device type. - Fill in the device's parameters, based on the communication information and in some cases the variable information. This is device type specific and is covered in Device types.
- Use the Validate button to validate the parameters and, in the case of a physical device, establish a connection to the device. If the parameters are not correct or if a connection can not be established an appropriate reason is displayed.
- Use the Save button to save the definition of the device. The device will appear in the list of devices for the node, in a Stopped state.