Technical data

SFBs for Compact CPUs
System Software for S7-300/400 System and Standard Functions - Volume 2/2
A5E00739858-01
28-63
Parameters Declaration Data type Range of
values
Default Description
L_CF_BYT
OUTPUT INT 0 to 255 0 Connection memory byte on
local CPU. This parameter is
only set for the duration of
one call.
(255: Means: no connection
memory)
L_CF_BIT
OUTPUT INT 0 to 7 0 Connection memory bit on
local CPU. This parameter is
only set for the duration of
one call.
LEN
INPUT/
OUTPUT
INT 0 to 1024 0 Length of message frame,
number in bytes (This
parameter is only set for the
duration of one call).
Data Consistency
Data consistency is limited to 128 bytes. If you want to consistent data
transmission exceeding these 128 bytes, you must take the following into account:
Use the connection memory function. Do not access the data until they are
completely transmitted (evaluation of the connection memory specified for this job;
the connection memory is active for a call on SFB if NDR = TRUE). Do not reset
the connection memory to FALSE unless you have processed the data.
See also:
Additional Error Information of the SFBs 60 to 65