Siemens S7-300 Manual page 17

Temperature error (with
reference to the input range)
Linearity error (with
reference to the input range)
Repeat accuracy (steady
state at 25 _C, with
reference to the input range)
Status, Interrupts, Diagnostics
Interrupts
S
Hardware interrupt
S
Diagnostic interrupt
Diagnostic functions
S
Group error display
S
Diagnostics information
read-out
2.1 Clock synchronization
Characteristics
Reproducible response times (i.e. times of the same length) are achieved in
SIMATIC by means of an equidistant DP bus cycle and the synchronization of the
following free-running individual cycles:
S Free-running cycle of the user program. On account of cyclic program branches
the length of the cycle time may vary.
S Free-running, variable DP cycle on the PROFIBUS subnet.
S Free-running cycle on the DP slave backplane bus.
S Free-running cycle at signal conditioning and conversion in the electronic
modules of the DP slaves.
With equidistance the DP cycle runs with the same clock pulse and for the same
length. The priority classes of a CPU (OB 61 to OB 64) and the clocked I/Os are
synchronized with this clock pulse. The I/O data are thus transferred at defined,
fixed intervals (clock synchronization).
Product Information on the Manual S7-300 Module Specifications, Edition 11/2002
A5E00213444-02
" 0.004 %/K
" 0.03 %
" 0.1 %
Parameters can be
assigned
Parameters can be
assigned
Red LED (SF)
Possible
Data for Selecting a Sensor
Input range (rated
values)/Input resistance
S
Voltage
S
Current
Maximum input voltage for
voltage input (destruction
limit)
Maximum input current for
current input (destruction
limit)
Connection of the sensor
S
For measuring voltage
S
For measuring current
As two-wire transmitter
As four-wire transmitter
S
Load of the 2-wire
transmitter
(at L+ = DC 24 V)
Characteristic linearization
"1 V
/10 MΩ
" 5 V
/100 kΩ
" 10 V
/100 kΩ
1 to 5 V; /100 kΩ
" 20 mA /50 Ω
/50 Ω
0 to 20 mA;
/50 Ω
4 to 20 mA:
max. 20 V continuous;
75 VDC for no more than
1 s (pulse duty factor
1 : 20)
40 mA
Possible
Possible
Possible
max. 820 Ω
None
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