Siemens SIMATIC S5 Manual page 272

Assignment of the flag area:
F 0.0 "RLO 0"
F 0.1 "RLO 1"
FY 4 corresponds to IB 4
FY 5 corresponds to IB 5
FY 6 corresponds to IB 6
FY 7 corresponds to IB 7
FY 8 corresponds to QB 4 or QB 8 with the S5-115U
FY 9 corresponds to QB 5 or QB 9 with the S5-115U
FY 10 corresponds to QB 6 or QB 10 with the S5-115U
FY 11 corresponds to QB 7 or QB 11 with the S5-115U
F 15.0 edge trigger flag for parameter assignment error
F 15.1 pulse flag for parameter assignment error
FW 20 old value of IW 4
FW 22 pulse flag for IW 4 (edge evaluation)
FY 24 channel number
F 25.0 old value of I 7.5
F 26.0 pulse flag for I 7.5 (edge flag)
F 28.0 NEUA (only in the warm restart with S5-155U)
F 28.1 AFEH (only in the warm restart with S5-155U)
F 28.2 BFEH (only in the warm restart with S5-155U)
F 28.3 SFEH (only in the warm restart with S5-155U)
FY 29 KANR (only in the warm restart with S5-155U)
FW 30 FMLD (only in the warm restart with S5-155U)
FY 100 image of FY 255 when FB 162 is called in the start-up program
(only with S5-155U)
FY 200 – FY 255 scratchpad flags
Assignment of the system data area (S5-135U)
RS 60 scratchpad flags
RS 61 scratchpad flags
IP244
C79000–B8576–C862–02
Test Program
6–7