Siemens DP, S7-300F-2 PN - page 28

Industry Automation and Drive Technologies - SCE
TIA Training Document Page 28 of 65
Module E11
Status: 01/2010 Radio Frequency Identification (RFID) with SIMATIC S7-300F-2PN/DP and
RF180C
DB47 Request Data Block
The DB47 is set by means of the UDT11 in DB45.
In DB47, a UDT21 is embedded for each reader.
The request commands are then entered in the respective UDT21.
The data of the read/write request is then stored in DB48.
The reference to DB48 is assigned in UDT21 of DB47.
Generate DB47
Open DB47 and add UDT21 for each request
Open DB47 and for Reader1, insert the UDT21 five times by means of ARRAY format.
For Reader2, also insert UDT21 five times by means of ARRAY format.
Note
In our example, five request commands are possible for each reader or channel.
Thus, the UDT21 is embedded in DB47 10 times.
The commands or requests of the second reader start with address 50.