Siemens SIMATIC S5 CP 523 Manual page 218

Using the "SEND" and "RECEIVE" Function Blocks
8.2.5 Flags in "RECEIVE" FB 201
Explanation of the flags used by "RECEIVE" FB 201:
Table 8-4. Overview of the Flags Used by "RECEIVE" FB 201
Flag
F 255.0
F 254.7
FY 254
FY 246
FW 230
FW 232
FW 234
FW 236
FW 238
FW 240
FW 242
FW 244
8-28
Symbol
Auxiliary flag for buffering the RLO at jump
H-FLAG-1
Auxiliary flag for STAT bit "Data available"
H-FLAG-3
Auxiliary flag byte for buffering STAT
H-BYTE-1
Auxiliary flag byte for processing the last
H-BYTE-2
message block
"Number of data words fetched from the CP
ZLAE-REG
(= ZLAE parameter") register
Auxiliary register for storing length of
Z-DB-LAE
destination DB
Module address index register for word-serial
BADR-IND
reading from CP
Register for Z-DB start address for DWs (DO FW
ZANF-REG
register, store data words in Z DB)
B-AN-E "Number of message blocks" register
ANZ-E-W Number of words to be received
Module address register (DO FW register for CP
BADR-REG
access)
W-LE-BL Number of words in last message block
Meaning
EWA 4NEB 811 6044-02a
CP 523