1-3
Section
Structure and Operation
13
1-3-2 Operating Modes
CPM2A CPU Units have 3 operating modes: PROGRAM, MONITOR, and RUN.
The program cannot be executed in PROGRAM mode. This mode is used to
perform the following operations in preparation for program execution
•
Changing initial/operating parameters such as those in the PC Setup
•
Writing, transferring, or checking the program
•
Checking wiring by force-setting and force-resetting I/O bits
The program is executed in MONITOR mode and the following operations can
be performed from a Programming Device. In general, MONITOR mode is used
to debug the program, test operation, and make adjustments.
•
Online editing
•
Monitoring I/O memory during operation
•
Force-setting/force-resetting I/O bits, changing set values, and changing pres-
ent values during operation
The program is executed at normal speed in RUN mode. Operations such as
online editing, force-setting/force-resetting I/O bits, and changing set values/
present values cannot be performed in RUN mode, but the status of I/O bits can
be monitored.
Note
When the PC is in RUN mode with a Programming Console connected to the
peripheral port, if a PT is connected to the RS-232C port via Host Link, the Pro-
gramming Console will display a message prompting the user to enter a pass-
word. (For details, refer to page 85.) This is because, in order to write data to the
PC, the PT automatically switches the operating mode from RUN mode to MON-
ITOR mode.
•
This automatic mode change will not be performed if the PT is connected via
NT Link.
•
When a Programming Device installed on a computer is connected to the
peripheral port, the display (at the computer) for the CPU Unit’s operating
mode will simply change from “RUN” to “MONITOR.”
1-3-3 Operating Mode at Startup
The operating mode of the CPM2A when the power is turned on depends upon
the PC Setup settings and the Programming Console’s mode switch setting if a
Programming Console is connected.
PC Setup setting
Programming Console
t d
Programming Console
t
t d
Word
Bits
Setting
g
g
connected
g
g
not connected
DM6600
08 to 15
00
Startup mode determined
by the mode switch
setting.
Startup mode is RUN
mode. (See note.)
01
Startup mode is the same as the operating mode
before power was interrupted.
02
Startup mode is determined by bits 00 to 07.
00 to 07
00
PROGRAM mode
01
MONITOR mode
02
RUN mode
Note
The default setting is 00. With this default setting, the startup operating mode is
determined by the Programming Console’s mode switch setting if a Program-
ming Console is connected to the Peripheral port. If a Programming Console is
not connected, the PC will automatically enter RUN mode.
PROGRAM Mode
MONITOR Mode
RUN Mode
