Technical data

Generating Block-Related Messages
System Software for S7-300/400 System and Standard Functions - Volume 2/2
A5E00739858-01
24-5
24.2 Generating Block-Related Messages without
Acknowledgment with SFB 36 "NOTIFY"
Description
SFB 36 "NOTIFY" monitors a signal. It generates a message both on a rising edge
(event entering state) and on a falling edge (event leaving state). You can have up
to ten associated values sent with the message. The message is sent to all stations
logged on for this purpose. When the SFB is first called, a message with the
current signal state is sent.
The associated values are queried when the edge is detected and assigned to the
message.
One memory with two memory blocks is available for each instance of SFB 36
"NOTIFY". For information on saving signal transitions to intermediate memory
refer to the section "Signal transition detection" in the Introduction to Generating
Block Related Messages with SFBs.
SFB 36 "NOTIFY" is compliant with IEC 1131-5.
Parameter Declaration Data Type Memory Area Description
SIG INPUT BOOL I, Q, M, D, L The signal to be monitored
ID INPUT WORD I, Q, M, D, L,
constant
Data channel for messages:
W#16#EEEE ID is only evaluated at the
first call.
EV_ID INPUT DWORD I, Q, M, D, L,
constant
Message number (0 not permitted) EV_ID
is only evaluated at the first call.
Subsequently, the message number used
for the first call applies to every call of
SFB 36 with the corresponding instance
DB.
STEP 7 assigns the message number
automatically to ensure consistency of the
message numbers. The message
numbers within a user program must be
unique.
SEVERITY INPUT WORD I, Q, M, D, L,
constant
Weighting of the event: Possible values:
0 through 127 (value 0 means highest
weighting)
This parameter is irrelevant for processing
the message.
DONE OUTPUT BOOL I, Q, M, D, L DONE status parameter: Generation of
message completed
ERROR OUTPUT BOOL I, Q, M, D, L ERROR status parameter
ERROR=TRUE indicates that an error has
occurred during processing. For details
refer to parameter STATUS.
STATUS OUTPUT WORD I, Q, M, D, L STATUS parameter: Displays error
information