Modicon M580 Safety-specific System Words
Original instructions
About us
Detailed Description
WARNING
UNEXPECTED APPLICATION BEHAVIOR
Do not use system objects (%Si, %SWi) as variable when they are documented.
Failure to follow these instructions can result in death, serious injury, or equipment damage.
Description of system words:
Word
Symbol
%SW128
Function
Force time synchronization for Safety IO
Initial State
-
With CPU firmware version earlier than 3.20, force time synchronization between internal NTP time and SAFE time into the safe IO modules and SAFE CPU task:
  • Value change from 16#1AE5 to 16#E51A forces synchronization.
  • Other sequences and values do not force synchronization.
%SW142
Function
Safety Copro FW version
Initial State
-
Contains the safety Copro firmware version in 4 digits BCD.
For example, firmware version 21.42 corresponds to %SW142 = 16#2142.
%SW152
Function
NTP CPU time status
Initial State
-
Status of the NTP CPU time, updated by Ethernet communication module over the X Bus backplane via the optional forced time synchronization feature:
  • 0: The CPU time is not refreshed by the Ethernet communications module.
  • 1: The CPU time is refreshed by the Ethernet communications module.
%SW169
Function
Safety application ID
Initial State
–
Contains an ID of the safety code part of the application. The ID is automatically modified when the safe application code is modified.
NOTE:
  • If the safe code has been changed and a Build Changes command has been executed since the previous Rebuild All command (thereby changing the Safety application ID), execution of a Rebuild All command may again change the Safety application ID.
  • The SAFE program unique identifier can be read using the SAID output of the system function block S_SYST_STAT_MX.
%SW172
Function
State of the SAFE task
Initial State
–
State of the SAFE task:
  • 0: No SAFE task exists
  • 1: Stop
  • 2: Run
  • 3: Breakpoint
  • 4: Halt