14 Test Operation, Adjustment, Maintenance and Troubleshooting
14.3 Operation and Test [Power ON and PLC Running]
170
FX3G Series Programmable Controllers
User's Manual - Hardware Edition
14.3 Operation and Test [Power ON and PLC Running]
14.3.1 Self-diagnostic function
When the PLC’s power is turned on, its self-diagnostic function starts automatically. If there are no problems
with the hardware, parameters or program, the PLC will start and the RUN command (refer to Section 14.2) is
given (RUN LED is lit). If any problems are found, the "ERR" LED flashes or lights.
14.3.2 Test functions
Functions of the programming tool to turn on/off the PLC devices and change the current values/settings are
effective or ineffective depending on the PLC status as shown below.
: Effective : Conditionally effective - : Ineffective
*1. Forcible ON/OFF
- The forcible ON/OFF function is effective on the input relays (X), output relays (Y), auxiliary relays (M), state
(S), timers (T) and counters (C). On the display module, the function cannot be operated for the input relays
(X).
- The forcible ON/OFF function can turn on or off the devices only for one scan.
While the PLC is running, the function is substantially effective in clearing the current values of the timers (T),
counters (C), data registers (D), index registers (Z and V) and extension registers (R) and in controlling the
SET/RST circuit and self-retaining circuit. (The operation to forcibly turn on timers is effective only when the
timers are driven by the program.)
- The results of forcible ON/OFF operation performed while the PLC in the stopped state or performed for
devices not used in the program are retained.
However, the results of the operation performed for the input relays (X) are not retained because the relays
refresh input even while the PLC is in the stopped state. (They are updated according to the input terminal
conditions.)
*2. Since the current values may be changed according to MOV instruction in the program and the operation results,
the most recently obtained values are retained.
*3. Only display modules can change the current value by the extension file register test function.
*4. Change of timer and counter settings
The settings of the timers (T) and counters (C) can be changed only when the timers are driven by the program.
14.3.3 Program modification function
The sequence program can be transferred while the PLC is running or in the stopped state as shown below.
: Effective - : Ineffective
*1. Since the writing function is used during running, the programming tool must be applicable to the writing function
white running, such as GX Developer.
Item
In running
status
In stopped
status
Forcible ON/OFF
*1
Devices used in program
*1 *1
Devices not in use
Change of current values of timers, counters,
data registers, extension registers, extension
file registers and file registers
Devices used in program
*2*3 *3
Devices not in use
*3 *3
Change of settings of timers and counters
*4
When the program memory is the built-in EEPROM
When the program memory is in the memory cassette
and the PROTECT switch is on
--
When the program memory is in the memory cassette
and the PROTECT switch is off
Item
In running
status
In stopped
status
Batch writing of file registers (D) and extension file registers (ER) -
Writing of program to PLC
Partial modification of program
*1
Modification of whole program (batch writing) -
Writing of parameters to PLC -
Writing of comments to PLC -