Inventory - Siemens SIMATIC RF650R Configuration Manual

7.6.2.2

Inventory

The "Inventory" block activates the taking of inventories. There are four different modes that
you can select with the "ATTRIBUTE" parameter.
● At the start, a certain duration/number (period of time, number of inventories, number of
"observed" events or identified transponders) is specified. A distinction is made between
the following options:
– Duration
– Number of inventories
– Number of "observed" events
Inventories are then taken by the reader for this time or number of inventories. When the
specified time/number is reached, the block is ended and returns all identified
transponders in "IDENT_DATA". The transponders are sorted according to the RSSI
value (highest value first). In other words, other commands can only be executed when
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.
● 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".
SIMATIC RF650R/RF680R/RF685R
Configuration Manual, 10/2015, C79000-G8976-C386-03
Take inventories for a specified period of time
Take a specified number of inventories
Take inventories until a specified number of transponders have been identified at the
same time.
Interface to the SIMATIC controller
7.6 Programming Ident blocks
109