Description of System Words %SW0 to %SW11
Original instructions
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NOTE: For M580 safety, the system word %SW4 has a specific meaning.
Detailed Description
Description of system words %SW0 to %SW11:
Word
Symbol
%SW0
MASTPERIOD
Function
Master task scanning period
Initial State
0
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: Yes Momentum: Yes Premium: Yes Atrium: Yes
This word is used to modify the period of the master task via the user program or via the terminal.
The period is expressed in ms (1...255 ms)
%SW0=0 in cyclic operation.
On a cold restart: it takes the value defined by the configuration.
%SW1
FASTPERIOD
Function
FAST task scanning period
Initial State
0
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: Yes Momentum: No Premium: Yes Atrium: Yes
This word is used to modify the period of the FAST task via the user program or via the terminal.
The period is expressed in milliseconds (1...255 ms).
On a cold restart, it takes the value defined by the configuration.
%SW2
AUX0PERIOD
%SW3
AUX1PERIOD
Function
Auxiliary task scanning period
Initial State
0
Platforms
M340: No M580: Yes M580 Safety: Yes Quantum: Yes(1) Momentum: No Premium: Yes(2) Atrium: Yes 
(1)
only on 140 CPU 6•• 
(2)
only on TSX 57 5•• PLCs.
These words are used to modify the period of the tasks defined in the configuration, via the user program or via the terminal.
The period is expressed in tens of ms (10 ms to 2.55 s).
%SW4
AUX2PERIOD
Function
Auxiliary task scanning period
Initial State
0
Platforms
M340: No M580: No M580 Safety: No(3) Quantum: Yes(1) Momentum: No Premium: Yes(2) Atrium: Yes 
(1)
only on 140 CPU 6•• 
(2)
only on TSX 57 5•• PLCs. 
(3)
%SW4 has a specific meaning.
The word is used to modify the period of the task defined in the configuration, via the user program or via the terminal.
The period is expressed in tens of ms (10 ms to 2.55 s).
%SW5
AUX3PERIOD
Function
Auxiliary task scanning period
Initial State
0
Platforms
M340: No M580: No M580 Safety: No Quantum: Yes(1) Momentum: No Premium: Yes(2) Atrium: Yes 
(1)
only on 140 CPU 6•• 
(2)
only on TSX 57 5•• PLCs.
This word is used to modify the period of the task defined in the configuration, via the user program or via the terminal.
The period is expressed in tens of ms (10 ms to 2.55 s).
%SW6
%SW7
Function
IP Address
Initial State
–
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: No Momentum: Yes Premium: No Atrium: No
These two words give the IP address of the CPU Ethernet port. Modification is not taken into account.
These two words are set to 0 if the CPU does not have an Ethernet link.
%SW8
TSKINHIBIN
Function
Acquisition of task input monitoring
Initial State
0
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: Yes Momentum: No Premium: Yes Atrium: Yes
Normally set to 0, this bit can be set to 1 or 0 by the program or the terminal.
It inhibits the input acquisition phase of each task:
  • %SW8.0 = 1 inhibits the acquisition of inputs relating to the MAST task.
  • %SW8.1 = 1 inhibits the acquisition of inputs relating to the FAST task.
  • %SW8.2 to 5 = 1 inhibits the acquisition of inputs relating to the AUX 0...3 tasks.
On Modicon M340:
CANopen IO are not affected by the word %SW8.
On Modicon M580:
DIO and EIO are not affected by the word %SW8.
On Quantum:
DIO and EIO are not affected by the word %SW8.
On Premium:
Premium High End CPU Ethernet port is affected by %SW8 which is used to monitor the Inputs.
Premium Legacy CPU Ethernet port is affected by %SW8 which is used to monitor the Outputs.
%SW9
TSKINHIBOUT
Function
Monitoring of task output update
Initial State
0
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: Yes Momentum: No Premium: Yes Atrium: Yes
Normally set to 0, this bit can be set to 1 or 0 by the program or the terminal.
Inhibits the output updating phase of each task:
  • %SW9.0 = 1 assigned to the MAST task; outputs relating to this task are no longer managed.
  • %SW9.1 = 1 assigned to the FAST task; outputs relating to this task are no longer managed.
  • %SW9.2 to 5 = 1 assigned to the AUX 0...3 tasks; outputs relating to these tasks are no longer managed.
On Modicon M340:
  • Inputs/outputs distributed via CANopen bus are not affected by the word %SW9.
  • After an operating mode, outputs are in Security mode state equal to 0 while the bit is set.
  • For IO scanning, the Inputs are monitored by %SW9.0.
On Modicon M580:
DIO and EIO are not affected by the word %SW9.
On Quantum:
DIO and EIO are not affected by the word %SW9.
On Premium:
Premium High End CPU Ethernet port is affected by %SW9 which is used to monitor the Outputs.
Premium Legacy CPU Ethernet port is affected by %SW9 which is used to monitor the Inputs.
WARNING
UNEXPECTED APPLICATION BEHAVIOR - OUTPUTS DEACTIVATION
Before deactivating an Output, take into account its deactivation mode (fallback or maintain).
Failure to follow these instructions can result in death, serious injury, or equipment damage.
CAUTION
UNEXPECTED APPLICATION BEHAVIOR
Before setting the %SW9 value to 1, ensure that the output behavior will remain appropriate:
On Premium/Atrium:
Module outputs located on the X Bus automatically switch to the configured mode (fallback or maintain). On the Fipio bus, certain devices do not manage fallback mode; then only maintain mode is possible.
On Quantum:
All outputs, as well as the local or remote rack (RIO) are maintained in the state that preceded the switch to 1 of the %SW9 bit corresponding to the task.
The Distributed Inputs/Outputs (DIO) are not assigned by the system word %SW9.
Failure to follow these instructions can result in injury or equipment damage.
Word
Symbol
%SW10
TSKINIT
Function
First cycle after cold start
Initial State
0
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: Yes Momentum: Yes Premium: Yes Atrium: Yes
If the value of the current task bit is set to 0, this means that the task is performing its first cycle after a cold start:
  • %SW10.0: assigned to the MAST task.
  • %SW10.1: assigned to the FAST task.
  • %SW10.2 to 5: assigned to the AUX 0...3 tasks.
%SW11
WDGVALUE
Function
Watchdog duration
Initial State
-
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: Yes Momentum: Yes Premium: Yes Atrium: Yes
Reads the duration of the watchdog. The duration is expressed in milliseconds (10...1500 ms).
This word cannot be modified.
NOTE: The duration range in Quantum Safety PLCs is: 20...990 ms.
M580 Safety Specific Function
Description of system word %SW4 for M580 safety:
Word
Symbol
%SW4
Function
SAFE task scanning period
Initial State
0
Platforms
Only M580 Safety
The word is used to read the period of the SAFE task defined in the configuration. The period is not modifiable.