Connection Parameters

UNINTENDED EQUIPMENT OPERATION

Do not change these protocol parameters, except on the advice of Technical Support for this product.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

[OPCUA] Parameter

Description

Allowable Values

Default Value

BrowseTimeout

The browse timeout (in milliseconds).

This parameter specifies the amount of time that an OPC UA server browsing window will wait for a browse call to succeed on an OPC UA server. If browsing is not successful in this period of time, it will stop.

1- 1800000

60000 (ms)

ConnectionDelay

The connection delay between reconnection attempts.

If the connection to the server is unsuccessful, by default the driver will immediately try to reconnect. This parameter allows you to specify a delay before the next connection attempt occurs.

0-30000

0 ms

ConnectionTimeout

The connection timeout (in milliseconds). This parameter specifies the time in milliseconds that the driver will wait for a connection with the OPC UA server to be made.

1-100000

10000 ms

CallTimeout

The timeout in milliseconds for individual service calls. This parameter defines how long the driver will wait for a server response after sending a service call.

1-100000

10000 ms

DeviceInitializeTimeOut

Determines how long the driver will wait for the initialization procedures to complete before replying to the I/O server INIT_UNIT command.

When the driver receives the INIT_UNIT command, it connects to the OPC UA server. It then reads and adds the monitored items for all tags configured for the I/O device. It then sets the I/O device online and replies to the I/O server.

The driver monitors the time it takes to process the INIT_UNIT command. If it takes longer than the DeviceInitializeTimeOut value, it fails the command.

Normally this parameter is not required. However, in a case where you have a very large number of tags, you may need to increase it to make sure the I/O device is initialized and comes online correctly.

Note: This parameter value should be less than [IOServer]CancelTimeout, which is set to 300 seconds by default.

60 – 600 (seconds)

180

ItemsMaximumBlockSize

Maximum number of monitored items the driver can add or read in one request to the OPC UA server.

1-10000

100

SessionTimeout

The session timeout (in milliseconds) for the server connection. If the driver is unable to issue a request within this interval, the server will automatically stop the connection.

1 - 10000000 ms

3600000

StatusItemNodeId

The status item Node ID.

If this parameter is specified, the driver will only put the I/O device online if the value of this item is equal or greater than the value specified for the StatusItemValue parameter (see below).

For example, if the standard OPC UA ServiceLevel item is used as the status item, these parameters can be set as follows:

StatusItemNodeId=i=2267

StatusItemValue=200

-

Not specified.

StatusItemValue

The comparison value for the status item specified by the StatusItemNodeId parameter (see above).

0 – 1000000

0

UseSamplingMonitoringMode

When a tag is not subscribed in Plant SCADA, the driver sets the OPC UA item monitoring mode to Disabled. This parameter allows you to set it to Sampling mode instead.

This can be useful in case where the OPC UA server does not publish the current item value after the tag is subscribed and the driver changed the item monitoring mode from Disabled to Reporting.

0 – monitoring mode is set to Disabled for unsubscribed tags

1 - monitoring mode is set to Sampling for unsubscribed tags

0

WatchdogTime

The time (in milliseconds) between watchdog checks. This parameter defines how often the driver will perform watchdog read to check the connection to the server.

1- 100000

10000 ms

WatchdogTimeout

The timeout (in milliseconds) for a specific watchdog check.

1- 100000

10000 ms