Technical data

Table Of Contents
Common Parameters for SFCs
System Software for S7-300/400 System and Standard Functions - Volume 1/2
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A5E00709327-01
2.2 Meaning of the Parameters REQ, RET_VAL and BUSY
with Asynchronous SFCs
Asynchronous SFCs
SFCs that operate asynchronously are SFCs that are called more than once before
they complete their functions. The following SFCs are either always executed
asynchronously or in certain situations:
SFC 7 "DP_PRAL"
SFC 11 "DPSYC_FR"
SFC 12 "D_ACT_DP"
SFC 13 "DPNRM_DG"
SFC 51 "RDSYSST"
SFC 55 "WR_PARM"
SFC 56 "WR_DPARM"
SFC 57 "PARM_MOD"
SFC 58 "WR_REC"
SFC 59 "RD_REC"
SFC 65 "X_SEND"
SFC 67 "X_GET"
SFC 68 "X_PUT"
SFC 69 "X_ABORT"
SFC 72 "I_GET"
SFC 73 "I_PUT"
SFC 74 "I_ABORT"
SFC 82 "CREA_DBL"
SFC 83 "READ_DBL"
SFC 84 "WRIT_DBL"
SFC 90 "H_CTRL"
SFC 102 "RD_DPARA"
SFC 103 "DP_TOPOL"
SFC 114 "PN_DP"