Technical data

SFCs and SFBs for Updating the Process Image and Processing Bit Fields
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
14-11
When the block is called for the first time, you must set 1 at the RESET input.
When the sequencer is in the last step (DSC has the value LST_STEP) and when
the execution time for this step has expired, outputs Q and EOD are set and the
SFB remains in the last step until you set 1 at the RESET input.
A DRUM timer runs only in the STARTUP and RUN modes.
The operating system resets SFB 32 "DRUM" during a cold restart but not during a
warm restart. If you want to initialize SFB 32 "DRUM" after a warm restart, call it
with RESET = 1 in OB100.
Parameter Declaration Data Type Memory Area Description
RESET INPUT BOOL I, Q, M, D, L, constant Signal level 1 resets the sequencer.
When calling the block for the first
time, you must set RESET to 1.
JOG INPUT BOOL I, Q, M, D, L, constant A rising edge (compared to the last
SFB call) switches the sequencer to
the next step if it is not yet in the last
step. The next step is enabled
depending on the value you assign to
DRUM_EN.
DRUM_EN INPUT BOOL I, Q, M, D, L, constant Control parameter that specifies
whether time-dependent switching to
the next step is possible (1: time-
dependent switching possible)
LST_STEP INPUT BYTE I, Q, M, D, L, constant Number of the last step;
possible values: 1 to 16
EVENT,
1 <
i < 16
INPUT BOOL I, Q, M, D, L, constant Event bit number i (belongs to step i)
OUTj,0
<
j < 15
OUTPUT BOOL I, Q, M, D, L Output bit number j (identical to the bit
number j of OUT_WORD)
Q OUTPUT BOOL I, Q, M, D, L Status parameter that specifies
whether the execution time you
selected for the last step has expired.
OUT_WORD OUTPUT WORD I, Q, M, D, L, P Output bits collected together in a
variable
ERR_CODE OUTPUT WORD I, Q, M, D, L, P If an error occurs during execution of
the SFB, ERR_CODE contains the
error information.
JOG_HIS VAR BOOL I, Q, M, D, L, constant (No relevance for the user: JOG input
parameter of the previous SFB call)
EOD VAR BOOL I, Q, M, D, L, constant Identical to the output parameter Q
DSP VAR BYTE I, Q, M, D, L, P,
constant
Number of the first step;
possible values: 1 to 16
DSC VAR BYTE I, Q, M, D, L, P,
constant
Number of the current step
DCC VAR DWORD I, Q, M, D, L, P,
constant
The execution time still remaining in
the current step in ms (only relevant if
DRUM_EN = 1 and the corresponding
event bit is set to = 1)
DTBP VAR WORD I, Q, M, D, L, P,
constant
The time base valid for all steps in ms