Global Session Mechanism - Balluff BIS U-6127-081-1 4-06-ST36 Betriebsanleitung

BIS U-6127-081-1_4-06-ST36
Processor unit
9
OPC UA (continued)
3. To access the desired event, the B
object must be expanded. Select
Rfid uhf /S
eRveR
the R S e t event under
fid can vent ype
S e - a i S
imple ventS uto d can
setting with a (bottom right in the Event View).
pply
Fig. 9-42: Event View
As soon as asynchronous operation is started with the
ScanStart() method (see page 146), an event is generated
for each detected data carrier. These are displayed in the
e window under the e
ventS vent
indicates that it is an R S
fid can
To get more information about the event, you just have to
click on the event. All data are then displayed in the d
window.
Information about the exact dates can be found under the
Events chapter (see page 165).
Fig. 9-43: Event Details
www.balluff.com
BiS u-6127
alluff
e t and accept the
vent ype
tab. The e t
vent ype
e t (see page 165).
vent ype
etailS
9.9.9

Global Session Mechanism

In OPC UA, there are session-related variables as well as
global variables. The global variables are valid for all active
and new sessions. An example of this is the l
variable. It is used by all sessions.
The clients are pictured in Fig. 9-44 and Fig. 9-45. Both
values of the l S d variable are identical, as
aSt can ata
expected.
Fig. 9-44: UaExpert Client 1
Fig. 9-45: UaExpert Client 2
If you run the scan method on client 1, only the
EPC 0809080808080808080808 is detected and the
l S d variable is set to this value. Since all sessions
aSt can ata
use this variable, the value changes on both clients (see
Fig. 9-46 and Fig. 9-47).
Fig. 9-46: Client 1: Variable LastScanData
Fig. 9-47: Client 2: Variable LastScanData
However, if you want to know the last detected tag of the
individual session, you have to use the GetLastScanData()
method. This is session-related and returns the desired
value. In the case of this example, the method therefore
returns the value 0809080808080808080808 for the client
(see Fig. 9-48) and 011000202000000001121014 for
client 2 (see Fig. 9-49).
Fig. 9-48: Client 1: Method GetLastScanData
S d
aSt can ata
english 171