Siemens SIMATIC S7-300 FM 350-1 Manual page 45

Time Required to Transfer Values
Table 5- 6 Time Required to Transfer Values
Use of the FM 350-1
Centralized
Distributed
(Non-isochronous mode)
Distributed
(Isochronous mode)
Parameters for Transferring Values in the DB (Count Modes)
The following table shows the range of the DB in which you transfer the LOAD_VAL,
CMP_V1 and CMP_V2 parameters.
The LOAD_VAL parameter (bytes 14 to 17) has two meanings:
● If you set function parameter L_DIRECT or L_PREPAR, LOAD_VAL is interpreted as a
● If you set function parameter C_DOPARA, you can use Byte 14 to define the behavior of
Table 5- 7 Parameters for Transferring Values in the DB (Count Modes)
DB address Parameters
14.0 LOAD_VAL
14.0 LOAD_VAL
FM 350-1 Counter module
Manual, 05/2011, A5E03648639-01
Time requirement
At least 4 OB 1 cycles
At least 5 PROFIBUS DP cycles
At transmission of
only one value
At simultaneous
initiation of the
transmission of
several values
load value.
outputs DO0 and DO1. Bytes 15 and 16 are interpreted as hysteresis and pulse duration.
Meaning
Load value; direct and preparatory loading with function parameter L_DIRECT
Load value; preparatory loading with function parameter L_PREPAR
The behavior of outputs DO0 and DO1, hysteresis and pulse duration, are defined using
function parameter: C_DOPARA
Bit 3 Bit 2
x 0
x 0
x 0
x 0
x 1
x 1
5 PROFIBUS DP cycles
for the 1st value: 5 PROFIBUS DP cycles after initiation

for the 2nd value: 6 PROFIBUS DP cycles after initiation

for the 3rd value: 7 PROFIBUS DP cycles after initiation

Bit 1 Bit 0 Reaction of output DO0
0 0 Inactive
0 1 Active from comparison value to overflow
1 0 Active from comparison value to underflow
1 1 Active on reaching the comparison value for pulse
duration (up/down)
0 0 Active on reaching the comparison value for pulse
duration (up)
0 1 Active on reaching the comparison value for pulse
duration (down)
Programming the FM 350-1
5.2 The function FC CNT_CTL1 (FC 2)
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