Omron CPM2C-S100C, Operation Manual, Page: 39 / 269

17
CPM2C-S Structure and Operation Section 1-3
1-3 CPM2C-S Structure and Operation
1-3-1 CPM2C-S Structure
The following diagram shows the internal structure of the CPU Unit.
I/O Memory The program reads and writes data in this memory area during execution.
Part of the I/O memory contains the bits that reflect the status of the PC’s
inputs and outputs. Parts of the I/O memory are cleared when the power is
turned ON and other parts are retained.
Note Refer to SECTION 4 Memory Areas for more details on I/O memory.
Program This is the program written by the user. The CPM2C-S executes the program
cyclically. (Refer to
1-3-5 Cyclic Operation and Interrupts for details.)
The program can be divided broadly into two parts: the “main program” that is
executed cyclically and the “interrupt programs” that are executed only when
the corresponding interrupt is generated.
PC Setup The PC Setup contains various startup and operating parameters. The PC
Setup parameters can be changed from a Programming Device only; they
cannot be changed from the program.
Some parameters are accessed only when PC’s power supply is turned ON
and others are accessed regularly while the power is ON. It will be necessary
to turn the power OFF and then ON again to enable a new setting if the
parameter is accessed only when the power is turned ON.
Note Refer to 4-6 PC Setup for details on the PC Setup.
Communications
Switches The Communications Switches determine whether the peripheral port and
RS-232C port connected through the communications port operate with the
External
input
devices
I/O memory
Program
PC Setup
Commu-
nications
port
Settings
Settings
Settings
External
output
devices
Communications
switches
DeviceNet
Master
CompoBus/S
Slaves
De
viceNet
interf
ace
CompoBus/S interf
ace
Input circuits
Output circuits