CPU
S
pecifications
and
Operation
4--6
CPU Specifications and Operation
DL105 PLC User Manual, 3rd Edition
There are two possible operating modes available with DL105 Micro PLCs.
S
RUN — executes program and updates I/O points.
S
PROGRAM — allows program changes. The CPU halts execution of the
ladder program and all output points are turned off.
The DL105 operates as follows when the power is connected.
1. The DL105 CPU will normally power-up in the mode that it was in just prior
to the power interruption. For example, if the CPU was in Program Mode
when the power was disconnected, the CPU will power-up in Program
Mode (see warning note below).
2. You can configure the DL105 to always power-up in the Run Mode. You can
set bit 13 in V7633 (nonvolatile memory) to enable this feature; we’ll show
you how to set the bit later in this chapter.
WARNING: If bit 13 in memory location V7633 is
not set
, once the super
capacitor has discharged the system memory may not retain the previous
mode of operation. When this occurs, the PLC can power-up in either Run or
Program Mode. There is no way to determine which mode will be entered.
Failure to adhere to this warning greatly increases the risk of unexpected
equipment startup.
The DL105 Micro PLC does not have an
external switch to switch CPU operating
modes. You have to use a programming
device, such as the handheld programmer
or
Direct
SOFT, to change the operating
mode.
You can use either
Direct
SOFT or the Handheld Programmer to change the CPU
mode of operation. With
Direct
SOFT you use a menu option in the PLC menu. With
the Handheld Programmer, you use the MODE key.
Menu Options
MODE
Key
CPU Modes
Mode of Operation
at Power-up
Changing Modes in
the DL105 PLC
Summary of Contents for DL105
Page 2: ...DL105 PLC User Manual Manual Number D1 USER M...
Page 308: ...1B DL105 Error Codes In This Appendix Error Code Table...
Page 314: ...1C Instruction Execution Times In This Appendix Introduction Instruction Execution Times...
Page 324: ...1D Special Relays In This Appendix DL105 PLC Special Relays...
Page 327: ...1E PLC Memory In This Appendix DL105 PLC Memory...