COLD RESTART
RETENTIVE COLD RESTART
System
program
activities
(continued)
Table 4-4 continued:
Set system parameters according to default
in DX 0
No evaluation of DX 0
Call user interface OB 20
(if it exists)
1)
Call user interface OB 21/22
(if it exists)
1)
Synchronize start-up in multiprocessor
operation
Synchronize start-up in multiprocessor
operation
Transition to the cycle:
- switch BASP inactive
- call OB 1
Transition to the cycle:
- switch BASP inactive
- call OB 1
1) After POWER ON, the user interfaces are called in the following order during START-UP:
OB 38, OB 39, OB 20/OB 22.
4.3.6
User Interfaces for Start-Up
The organization blocks OB 20, OB 21 and OB 22 serve as user
interfaces for the various types of start-up. You can store your STEP 5
program for the type of start-up in these blocks.
OB 20
When the CPU executes a MANUAL or AUTOMATIC COLD
RESTART, the system program calls OB 20 once. In OB 20, you can
store a STEP 5 program which is responsible for preliminary steps for
a cold restart of cyclic processing prior to the execution of the cyclic
program.
You can, for example:
••
set flags
••
start timers (the start is executed by the system program when it en-
ters the RUN mode)
••
set default values for data to be output to I/O modules
••
synchronize CPs.
After processing OB 20, the cyclic program begins by calling OB 1.
If OB 20 is not loaded, the CPU begins the cyclic program
execution immediately after the COLD RESTART is completed
(following the system activities).
START-UP Mode
CPU 948 Programming Guide
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C79000-G8576-C848-04
Summary of Contents for CPU 948
Page 10: ...Contents CPU 948 Programming Guide 1 2 C79000 G8576 C848 04 ...
Page 32: ...Contents CPU 948 Programming Guide 2 2 C79000 G8576 C848 04 ...
Page 72: ...Data Blocks CPU 948 Programming Guide 2 42 C79000 G8576 C848 04 ...
Page 74: ...Contents CPU 948 Programming Guide 3 2 C79000 G8576 C848 04 ...
Page 154: ...Contents CPU 948 Programming Guide 4 2 C79000 G8576 C848 04 ...
Page 200: ...Contents CPU 948 Programming Guide 5 2 C79000 G8576 C848 04 ...
Page 308: ...Contents CPU 948 Programming Guide 7 2 C79000 G8576 C848 04 ...
Page 324: ...Examples of Parameter Assignment CPU 948 Programming Guide 7 18 C79000 G8576 C848 04 ...
Page 326: ...Contents CPU 948 Programming Guide 8 2 C79000 G8576 C848 04 ...
Page 370: ...Addressable System Data Area CPU 948 Programming Guide 8 46 C79000 G8576 C848 04 ...
Page 372: ...Contents CPU 948 Programming Guide 9 2 C79000 G8576 C848 04 ...
Page 486: ...Contents CPU 948 Programming Guide 11 2 C79000 G8576 C848 04 ...
Page 522: ...PG Functions via the S5 Bus CPU 948 Programming Guide 11 38 C79000 G8576 C848 04 ...
Page 524: ...Contents CPU 948 Programming Guide 12 2 C79000 G8576 C848 04 ...
Page 538: ...Contents CPU 948 Programming Guide 13 2 C79000 G8576 C848 04 ...
Page 546: ...List of Key Words CPU 948 Programming Guide Index 6 C79000 G8576 C848 04 ...