Technical data

S7 Communication
System Software for S7-300/400 System and Standard Functions - Volume 2/2
A5E00739858-01
21-47
21.16 Querying the Status of the Connection Belonging to an
SFB Instance with SFC 62 "CONTROL"
Description
With SFC 62 "CONTROL," you can query for S7-400 the status of a connection
belonging to a local communication SFB instance.
After calling the system function with the value 1 at control input EN_R, the current
status of the connection belonging to the communication SFB instance selected
with I_DB is queried.
Parameter Declaration Data Type Memory Area Description
EN_R INPUT BOOL I, Q, M, D, L,
constant
The enabled to receive control parameter
signalizes that the unit is ready to receive
when the input is set.
I_DB INPUT BLOCK_DB I, Q, M, D, L,
constant
Number of the instance DB
OFFSET INPUT WORD I, Q, M, D, L,
constant
Number of the data record in the multiple
instance DB (if no multiple instance DB
exists, 0 must be entered here).
RET_VAL OUTPUT INT I, Q, M, D, L Error information
ERROR
STATUS
OUTPUT
OUTPUT
BOOL
WORD
I, Q, M, D, L
I, Q, M, D, L
ERROR and STATUS state parameters,
error display:
ERROR=0 and STATUS has the value:
0000H: neither warning nor error
<> 0000H: Warning, STATUS supplies
detailed information.
ERROR=1
There is an error. STATUS supplies
detailed information on the type of
error.
I_TYP OUTPUT BYTE I, Q, M, D, L Identifier for the block type belonging to the
selected instance
I_STATE OUTPUT BYTE I, Q, M, D, L • = 0: The corresponding SFB instance
has not been called since the last
cold/warm restart or loading.
• <> 0: The corresponding SFB instance
has been called at least once since the
last cold/warm restart or loading.
I_CONN OUTPUT BOOL I, Q, M, D, L Status of the corresponding connection,
possible values:
• 0: Connection down or not
established
• 1: Connection exists
I_STATUS OUTPUT WORD I, Q, M, D, L Status parameter STATUS of the queried
communication SFB instance