OPC Status Tag Parameters

[OPCStatusTags] Parameter

Allowable Values

Default Value

Description

StartWait

time in milliseconds
- or -
–1 (infinite)

30000 (milliseonds)

On driver startup, this parameter determines the time the OPC driver will wait before requesting status tag data for an OPC I/O device.

The OPC server should respond within a few seconds. The default wait time of 30 seconds is usually adequate.

Default.Tag

An OPC item name

STATUS

This parameter specifies the default OPC item to be monitored at runtime to determine the operational status of an associated device.

Note: This parameter implements a global setting for all OPC I/O devices, unless it is specifically overridden using the equivalent OPC Device-specific Parameters.

Default.Update

0 -32000 (milliseconds)

The scan rate from Address field in the Plant SCADABoards configuration.

This parameter specifies the default update rate for OPC status tags at runtime. This is the frequency with which the OPC server polls the device for status tag values and then updates its own cache.

This parameter controls polling performed by the OPC server, not by Plant SCADA. The scope of the parameter is communication between the OPC server and a device, not between the OPC server and Plant SCADA.

Note: This parameter implements a global setting for all OPC I/O devices, unless it is specifically overridden using the equivalent OPC Device-specific Parameters.

Default.Condition

<condition>

(see table below)

ISGOOD

This parameter is used to determine if the OPC device is online at runtime, by comparing the <Condition> with the value of the default OPC item named in the .Default.Tag parameter.

If the specified condition is determined to be true, the device will be considered online.

This parameter represents the default condition for all OPC status tags, unless it is individually overridden using the OPC Device-specific Parameters.