Structure And Operation; Cpu Unit Structure - Omron CPM2C Operation Manual

Structure and Operation

1-3

Structure and Operation

1-3-1

CPU Unit Structure

I/O Memory
Program
PC Setup
Communications Switch
14
2. Although a CPM2C-CN111 can be connected to a CPM2C-CIF01-V1, it is
not possible to use the peripheral port and the RS-232C port on the
CPM2C-CN111 simultaneously. If an attempt is made to use both ports si-
multaneously, communications will not be performed properly and incor-
rect operation may result.
The following diagram shows the internal structure of the CPU Unit.
External
input
devices
Commu-
nications
port
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 3 Memory Areas in the Programming Manual (W353) for
more details on I/O memory.
This is the program written by the user. The CPM2C 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.
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 Section 1 PC Setup in the Programming Manual (W353) for more
details.
The Communications Switch controls the communications settings for the
peripheral port and the RS-232C port.
I/O memory
Program
Settings
Settings
Settings
Communications
switch
Section 1-3
PC Setup
External
output
devices