Omron SYSMAC CV Series Operation Manual page 17

Overview of PC Operation
Control System Design
3. On paper, assign all input and output devices to I/O points on Units and de-
termine which I/O bits will be allocated to each. If the PC includes Special I/O
Units, CPU Bus Units, or Link Systems, refer to the individual Operation
Manuals or System Manuals for details on I/O bit allocation. ( Section 3
Memory Areas )
4. Divide the required control actions into processes that need to be treated as
individual sections and create an SFC program to control the flow of execu-
tion of the processes. Refer to the CV-series PCs Operation Manual: SFC
for details on the SFC program. If desired, you can also program the PC
without using an SFC program by setting the PC for ladder-only operation
from the CVSS/SSS.
5. Using relay ladder symbols, write a program that represents the sequence
of required operations within each process and their inter-relationships. If
you are using an SFC program, you will actually be writing transition pro-
grams and action programs within the SFC program. Be sure to also pro-
gram appropriate responses for all possible emergency situations. ( Section
4 Writing Programs, Section 5 Instruction Set, Section 6 Program Execution
Timing )
6. Write the program in the CVSS/SSS offline, and then switch to online opera-
tion and transfer the program to Program Memory in the CPU. The program
can also be written or altered online. Refer to the CVSS/SSS Operation
Manual for details.
7. Generate the I/O table with I/O Units installed. The I/O table can be gener-
ated either online from the CVSS/SSS, or edited offline and then trans-
ferred. Always turn the PC off and on after transferring the I/O table. The PC
will not run until the I/O table has been registered. Refer to the CVSS/SSS
Operation Manual for details.
8. The PC Setup controls a variety of basic options in PC operation (such as
the method of I/O refreshing and PC mode at start-up). The operating pa-
rameters in the PC Setup can be left in their default settings or changed with
the CVSS/SSS as required. Refer to Section 7 PC Setup for details.
9. Debug the program, first to eliminate any syntax errors, and then to find
execution errors. Refer to the three CVSS/SSS operation manuals for de-
tails on debugging operations. ( Section 8 Error Processing )
10. Wire the PC to the controlled system. This step can actually be started as
soon as step 3 has been completed. Refer to the CV-series PCs Installation
Guide and to other Operation Manuals and System Manuals for details on
individual Units.
11. Test the program in an actual control situation and carry out fine tuning as
required. Refer to the CVSS/SSS operation manuals for details on debug-
ging operations. ( Section 8 Error Processing )
12. Record two copies of the finished program on masters and store them safely
in different locations. Refer to the CVSS/SSS operation manuals for details.
Note 1. The date and time are not set when the CPU is shipped. Set the date and
time by the procedure described in the CVSS/SSS Operation Manuals .
2. There is an error log in the PC. This log can be cleared by turning ON the
Error Log Reset Bit (A00014).
Designing the Control System is the first step in automating any process. A PC
can be programmed and operated only after the overall Control System is fully
understood. Designing the Control System requires, first of all, a thorough un-
derstanding of the system that is to be controlled. The first step in designing a
Control System is thus determining the requirements of the controlled system.
Section 1-5
5