BR.AN.PviServices .NET

Member Name

Description

Value

No

No access.

0

Read

Read access. ( KWPVATTR_READ ... AT=r ). Allows read access to the process data of a variable object. If this attribute is not specified, a read access to the variable data is rejected with Error 12035. In addition, PVI Manager doesn't carry out any cyclic read requests.

1

Write

Write access. ( KWPVATTR_WRITE ... AT=w ). Allows write access to the process data of a variable object. If this attribute is not specified, a write access attempt is rejected with Error 12034.

2

ReadAndWrite

ReadAndWrite access. ( KWPVATTR_READ | KWPVATTR_WRITE ... AT=rw )

3

EVENT

PLC event operation.. ( KWPVATTR_EVENT ... AT=e ). Operating mode as a line or PLC event variable. Monitoring for changes in the process data is carried out in the line or on the PLC. For this reason, PVI Manager doesn't need to carry out any cyclic read requests.

4

DIRECT

Direct event trigger in consequence of any data event. ( KWPVATTR_DIRECT ... AT=d ). This flag is only effective in connection with the Access.EVENT. A direct event trigger means that all process data returned by the line or PLC is sent directly to the application.

8

FASTECHO

Immediate write echo in consequence of a write access on the PV data. ( KWPVATTR_WRECHO ... AT=h ). When set, the time between a write request and a resulting "Data Change" event can be reduced. However, the write request itself cannot be accelerated with this (time between write request and write response). The write data is compared with the process image before the transfer to the PLC and, if there is a change, a "Data Changed" event is triggered.

16