Siemens Simatic S7-1500R System Manual page 166

Summary
The table below provides you with an overview of the relationships described above. It
shows in particular the possible values of the output parameters if execution of the
instruction is not complete after a call.
Note
You must evaluate the relevant output parameters in your program after each call
Table 7- 5 Relationship between REQ, STATUS/RET_VAL, BUSY and DONE during a "running" job.
Seq. no. Type of call
of the
call
1 First call
2 to (n - 1) Intermediate
call
n Last call
S7-1500R/H redundant system
System Manual, 10/2018, A5E41814787-AA
REQ STATUS/RET_VAL
1 W#16#7001
Error code (e.g.
W#16#80C3 for lack of
resources)
Not rele- W#16#7002
vant
Not rele- W#16#0000, if no errors
vant have occurred.
Error code if errors oc-
curred.
Basics of program execution
7.5 Asynchronous instructions
BUSY DONE
1 0
0 0
1 0
0 1
0 0
ERROR
0
1
0
0
1
165