Siemens SIMATIC RF650R Configuration Manual page 126

Programming via SIMATIC controller
8.5 Programming Ident blocks
all inventories have been taken completely. The unit (time or number) is specified using
"DUR_UNIT" and the value (time value or number) using "DURATION". This mode can
be executed using the attributes "0x80" and "0x81". Depending on the attribute, more or
less data is supplied about the identified transponders.
To be reported, a transponder must have had the "Observed" status at least once at the
start of or during the command execution time. The transponder is reported even if it
returned temporarily to the "Lost" status.
When this mode is active, commands relating to transponders are executed immediately,
even if no transponder is identified. This can have the result that the command is
terminated with an error message because there was no transponder in the antenna field
during command execution.
● With the attributes "0x86" (start "Presence_Mode") and "0x87" (end "Presence_Mode"),
inventories can be taken permanently. The presence of a transponder can then always
be queried using "PRESENCE" without needing to start the block with "EXECUTE". No
information about the identified transponders is returned when the command executes!
To obtain information about the identified transponders, use one of the two calls listed
above (with time / number of inventories = 0).
When this mode is active, commands relating to transponders are not executed
immediately but only when a transponder is identified. This achieves shorter reaction
times since the command is already pending when the transponder enters the antenna
field.
The "Presence_Mode" is practical in the context of the "Repeat command" function.
The "NUMBER_TAGS" output parameter is used to output the number of identified
transponders. With the attributes "0x80" and "0x81" on completion of the read operation, the
sum of all identified transponders is displayed. With the attribute "0x86" the number of
currently identified transponders is shown at the "NUMBER_TAGS" output parameter (max.
15), without needing to start the module with "EXECUTE".
Figure 8-12
126
"Inventory" block
SIMATIC RF650R/RF680R/RF685R
Configuration Manual, 03/2018, C79000-G8976-C386-06