Configuring The Operation Of The Cpu - Siemens SIMATIC S7 System Manual

98BDevice configuration

5.4 Configuring the operation of the CPU

5.4 Configuring the operation of the CPU
To configure the operational parameters
for the CPU, select the CPU in the
Device view (blue outline around whole
CPU), and use the "Properties" tab of the
inspector window.
Table 5- 2 CPU properties
Property
PROFINET interface
DI, DO, and AI
High-speed counters
(Page 315) and pulse
generators (Page 289)
Startup (Page 63)
Cycle (Page 73)
Communication load
System and clock memory
(Page 78)
Web server (Page 473)
Time of day
114
Description
Sets the IP address for the CPU and time synchronization
Configures the behavior of the local (on-board) digital and analog I/O
Enables and configures the high-speed counters (HSC) and the pulse generators used for
pulse-train operations (PTO) and pulse-width modulation (PWM)
When you configure the outputs of the CPU or signal board as pulse generators (for use with
the PWM or basic motion control instructions), the corresponding output addresses (Q0.0,
Q0.1, Q4.0, and Q4.1) are removed from the Q memory and cannot be used for other
purposes in your user program. If your user program writes a value to an output used as a
pulse generator, the CPU does not write that value to the physical output.
Startup after POWER ON: Selects the behavior of the CPU following an off-to-on transition,
such as to start in STOP mode or to go to RUN mode after a warm restart
Supported hardware compatibility: Configures whether modules (SM, SB, CM, CP or even
the CPU) can be substituted:
Allow acceptable substitute (default)

Allow any substitute

For example, a 16-channel SM could be an acceptable substitute for an 8-channel I/O.
Parameter assignment time for distributed I/O: Configures a maximum amount of time
(default: 60000 ms) for the distributed I/O to be brought online. (The CMs and CPs receive
power and communication parameters from the CPU during startup. This assignment time
allows time for the I/O connected to the CM or CP be brought online.)
The CPU goes to RUN as soon as the distributed I/O is online, regardless of the assignment
time. If the distributed I/O has not been brought online within this time, the CPU still goes to
RUN--without the distributed I/O.
Note: If your configuration uses a CM 1243-5 (PROFIBUS master), do not set this parameter
below 15 seconds (15000 ms) to ensure that the module to be brought online.
Defines a maximum cycle time or a fixed minimum cycle time
Allocates a percentage of the CPU time to be dedicated to communication tasks
Enables a byte for "system memory" functions and enables a byte for "clock memory"
functions (where each bit toggles on and off at a predefined frequency).
Enables and configures the Web server feature.
Selects the time zone and configures daylight saving time
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05