H1 Device Plugin

The whole H1 Device Plugin configuration is located in the node path /System/Devices/H1 Device.

An H1 Device Channel represents the connection to a H1 PLC.

To add a new H1 Channel, please follow these steps:

1. Add a Folder Node within the node H1 Device/Channels, or right-click on the H1 Device/Channels node and select Add Channel.
2. In the Add Channel dialog, specify the settings for the H1 connection.
   
3. After clicking on “Save”, the channel node is created.
4. You can start the channel by selecting the channel node and clicking the start button.
   

Within the node Variables you can create datapoint nodes which can be read and written from/to the PLC.
The Value Type property must be set to the corresponding operand type. Currently the following types are supported:

Note: 32-bit values (Float, Int32) will be read/written using two separate (16-bit) words. This can mean that if the value changes in the PLC while reading it, you might get an inconsistent value when one word has the new value but the other one has the old value.

Note: Bit values (Boolean) will be read/written as (16-bit) word. When writing such a boolean value, the word will be read from the PLC, then the bit(s) will be changed, and then the word will be written back to the PLC. This can mean that if at the same time some other party changes another bit in that word, that change might get lost.

The Path property of the node is used to specify the address and optionally the type and/or (for arrays) the length of the data. Currently, only Data Block (DB) is supported as data area.

DB<DB number>.D<Operand> <Offset>
DB<DB number>.D<Operand> <Offset>, <Length>
DB<DB number>.D<Operand> <Offset>, <Type>[<Length>]
DB<DB number>.DX <Offset>.<Bit>, <Length>

The H1 Device Plugin provides different status information depending on the layer to inspect. In general the channel-based diagnostic information is produced by the connection status of the channel to the PLC. The variable-based diagnostic information is produced during the read/write access of the different variables.

To monitor and diagnose the status of a H1 Channel, take a look at the following image:

The image above depicts the H1 Channel's Control Panel which displays all status relevant information. The control panel will automatically update its status information when a new status is available.

Status Circle

Color	Meaning
	The channel is stopped. Click the ► button to start it.
	The channel is currently in the progress of starting or stopping or is waiting to establish a connection.
	The channel is ready for doing read/write operations. You can stop it by clicking the ◼ button.
	The channel is running, but the connection is currently in an error state. Please check the status text for more information.

To monitor and diagnose the status of the different variables, take a look at the variable's Status property displayed in CoDaBix. Use the button “Read actual Value” to read the values from the PLC and store the result into the variables.

All channel related status information is also logged into the channel-specific log file stored in the [LoggingFolder]. Each log file is named in the naming scheme H1 Device.<ChannelName>.log.

The content of such a log file can look as follows:

...
2018-04-11 11:32:37.0 +2: [Error] Error (Severity=High): Code=[-1], Text=[The operation has timed-out.], Details=[]
...

The plugin's device type H1Device also defines the H1DeviceChannel and therefore extends the basic CodabixDevice and CodabixDeviceChannel entities. While the H1Device just represents a concretization of the CodabixDevice, the H1DeviceChannel extends the CodabixDeviceChannel with the H1 Variable Entities.

Each channel is handled by a channel worker which establishes a network connection to the PLC.

By default, the worker does not read any values. When a client or plugin requests a synchronous read of the channel's variables in CoDaBix (e.g. using the CoDaBix Web Configuration's function “Read actual value”), the channel worker reads them from the underlying PLC and then writes them into the corresponding CoDaBix Nodes.

Similarly, when a client or plugin writes values into the channel's variables, the channel worker will write those values to the underlying PLC.

To have an H1 variable being read steadily, you can edit the Node in the CoDaBix Web Configuration and set “History Options” to Yes (which will create an internal subscription), or you can use e.g. a OPC UA Client connected to the OPC UA Server plugin and create a subscription for the H1 variable Nodes. In these cases, the channel worker reads the variables from the PLC at a regular interval and, if the value of one of the variables has changed, writes the new value into the corresponding CoDaBix Node.