Siemens SIMATIC S7-200 System Manual page 57

The S7-200 Allows You to Set the States of Digital Outputs for Stop
Mode
The output table of the S7-200 allows you to determine whether to set the state of the digital
output points to known values upon a transition to the STOP mode, or to leave the outputs in the
state they were in before the transition to the STOP mode. The output table is part of the system
block that is downloaded and stored in the S7-200.
1. Select the View > Component >
System Block menu command
and select Output Table. Click on
the Digital tab.
2. To freeze the outputs in their last
state, select the Freeze Outputs
checkbox.
3. To copy the table values to the
outputs, enter the output table
values by clicking the checkbox for
each output bit you want to set to
On (1) after a run-to-stop transition.
The default values of the table are
all zeroes.
4. Click OK to save your selections.
5. Download the modified system
block to the S7-200.
The S7-200 Allows You to Configure the Value of Analog Outputs
The Analog Output Table allows you to set analog output points to known values after a
RUN-to-STOP transition, or to preserve the output values that existed before the transition to
STOP mode. The Analog Output table is part of the system block that is downloaded and stored in
the S7-200 CPU.
1. Select the View > Component >
System Block menu command
and select Output Table. Click on
the Analog tab.
2. To freeze the outputs in their last
state, select the Freeze Outputs
check box.
3. The Freeze Values table allows
you to set the analog outputs to a
known value (--32768 to 37262),
on a RUN-to-STOP transition.
4. Click OK to save your selections.
5. Download the modified system
block to the S7-200.
The S7-200 Allows You to Define Memory to Be Retained on Loss of
Power
You can define up to six retentive ranges to select the areas of memory you want to retain through
power cycles. You can define ranges of addresses in the following memory areas to be retentive:
V, M, C, and T. For timers, only the retentive timers (TONR) can be retained. The default setting for
the first 14 bytes of M Memory is to be non-retentive.
Only the current values for timers and counters can be retained: the timer and counter bits are not
retentive.
PLC Concepts
Figure 4-20 Digital Output Table
Figure 4-21 Analog Output Table
Chapter 4
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