User Manual

LOGO! functions
4.1 Constants and connectors
LOGO!
118 Manual, 06/2014, A5E33039675
Startup flag M8
LOGO! sets flag M8 in the first cycle of the circuit program. You can thus use it as a startup
flag in your circuit program. LOGO! resets M8 at the end of the first cycle.
You can use the M8 flag in all further cycles for setting, deletion and evaluation procedures
in the same way as other flags.
Backlight flags M25, M26, M28 to M31
The following flags control the backlight colors of the LOGO! onboard display or the LOGO!
TDE:
Backlight display
Flag
Remarks
White M25 The color white means LOGO!
is in RUN mode.
M26 The color white means LOGO!
TDE is in RUN mode.
Amber M28 The color amber means LOGO!
is in programming mode or
parameter assignment mode.
M30 The color amber means LOGO!
TDE is in programming mode,
parameter assignment mode or
TDE setting mode.
Red M29 The color red means LOGO!
has a diagnosis error.
M31 The color red means LOGO!
TDE has a diagnostics error.
Note:
The backlight lifetime of the LOGO! TDE is 20,000 hours.
Message text character set flag M27
The M27 flag selects between the two character sets that LOGO! uses to display message
texts. State 0 corresponds to Character Set 1, and state 1 corresponds to Character Set 2. If
M27=0 (low), LOGO! only displays message texts configured for Character Set 1; If M27=1
(high), LOGO! only displays message texts configured for Character Set 2. If you do not
include M27 in the circuit program, message texts display in the character set that you
selected from either LOGO!Soft Comfort or a LOGO! device.
Note
•
The output of the flag always carries the signal of the previous program cycle. This value
does not change within the same program cycle.
•
You can read or write flags from the network. If you have not added any special flags in
the diagram, but written them from the network, they can still work except M27. So if you
want to control character sets by M27, you must add it in the diagram first, and you can
connect M27 to NI blocks to control it from the network.