Plc Operating Modes; Stop Mode; Run Mode - AutomationDirect C0-USER-M Manual

Chapter 2: Specifications

PLC Operating Modes

Stop Mode

In Stop mode, the CLICK PLC does NOT execute the
ladder logic program or update the output points. The
primary use for Stop Mode is to enter or change a ladder
logic program. You also use Stop mode to set up the
PLC parameters, such as retentive memory areas, etc.
You can use CLICK Programming Software, or the
CLICK PLC mode switch to place the PLC in Stop
mode; however, the CLICK PLC mode switch will
override the software mode condition. If the PLC mode
switch is in the Stop position, the software is blocked
from changing the PLC mode. When the PLC mode
switch is in the Run position, the software may toggle
the mode switch from Run to Stop at will.

Run Mode

In Run mode, the PLC executes the application program and
updates the I/O system. You can perform many operations
during Run mode. Some of these include:
• Monitor and change I/O point status
• Change timer/counter preset values
• Change variable memory locations
The Run Mode can be divided into several key areas. For
the vast majority of applications, some of these execution
segments are more important than others. For example, you
need to understand how the PLC updates the I/O points,
handles forcing operations, and solves the application
program. The remaining segments are not that important
for most applications.
You can use CLICK Programming Software, or the CLICK
PLC mode switch to place the PLC in Run mode.
WARNING: Only authorized personnel fully familiar with all aspects of the application should make
changes to the ladder logic program. Make sure you thoroughly consider the impact of any changes to
minimize the risk of personal injury or damage to equipment.
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CLICK PLC Hardware User Manual, 6th Edition, Rev. F – C0-USER-M
Run/Stop
Mode Switch
Normal Run Mode Scan
Read Inputs
Service Peripherals, Force I/O
PLC Bus Communications
Update SC Relays & SD Registers
Execute the Ladder Program
Write Outputs
Diagnostics
C0-00DD1-D