Description of System Bits %S80 to %S97
Original instructions
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Detailed Description
Description of system bits %S80 to %S97:
Bit
Symbol
%S80
RSTMSGCNT
Function
Reset message counters
Initial State
0
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: Yes Momentum: Yes Premium: Yes Atrium: Yes
Normally set to 0, this bit can be set to 1 to reset the message counters %SW80 to %SW86.
%S82
Function
MB+PCMCIA polling adjust
Initial State
0
Platforms
M340: No M580: No M580 Safety: No Quantum: No Momentum: No Premium: Yes Atrium: Yes
This bit is used to change the request exchange mode with Mb+MBP100 PCMCIA.
By default (value 0), the system sends a request to the card and will poll for a response in the next MAST cycle.This mode is recommended for a small MAST duration.
When set to 1, the system sends a request to the card and waits for a response.This mode is recommended for a large MAST duration.
%S83
Function
Quantum Hot Standby remains primary on ERIO loss
Initial State
0
Platforms
M340: No M580: No M580 Safety: No Quantum: Yes(1) Momentum: No Premium: No Atrium: No 
(1)
Hot Standby only
NOTE: This bit is used in a configuration where both S908 RIO and Ethernet RIO drops are used. For configuration with Ethernet RIO drops only refer to %S84.
The bit is used to change the behavior of Quantum Hot Standby in case of loss of last Ethernet RIO drop.
  • When set to 0 (default value), if the last Quantum ERIO drop is lost, the primary goes offline and a switchover occurs.
  • When set to 1, if the last Quantum ERIO drop is lost, the primary remains primary as long as S908 drops are present. If no more S908 drops are present, then the primary goes offline and a switchover occurs.
%S83 value is automatically transferred from the primary CPU to the standby CPU. See the table at the end of this page which describes the System states depending on the %S83 and %S84 values.
%S84
Function
Quantum Hot Standby remains primary on ERIO loss
Initial State
0
Platforms
M340: No M580: No M580 Safety: No Quantum: Yes(1) Momentum: No Premium: No Atrium: No 
(1)
Hot Standby only
This bit is used to modify the behavior of the Quantum Hot Standby system in case of loss of last Ethernet RIO drop.
  • When set to 0 (default value), when the last Ethernet drop (Quantum Ethernet drop or X80 Ethernet drop) is lost, the primary goes offline and a switchover occurs. A manual action STOP -> RUN transition is needed to restart the system.
  • When set to 1, when the last Ethernet drop is lost, the primary remains primary as long as S908 drops are present. If no more S908 drops are present, then the primary goes offline and a switchover occurs.
%S84 value is automatically transferred from the primary CPU to the standby CPU. See the table at the end of this page which describes the System states depending on the %S83 and %S84 values.
%S88
Function
Quantum S908 RIO adapter swap over in M580 Architecture
Initial State
0
Platforms
M340: No M580: Yes M580 Safety: Yes Quantum: No Momentum: No Premium: No Atrium: No
In an M580 system with a redundant S908 network, this bit is used to force a Quantum S908 RIO adapter switchover.
By default the value is 0.
When set to 1, the system assigns the I/O management over the S908 network to the other Quantum S908 RIO adapter module.
The bit is reset automatically by the system.
NOTE: Check the status of the redundant Quantum S908 adapter before using the %S88. If the redundant Quantum S908 adapter is not healthy, the system will not perform the switchover even if the %S88 is set to 1.
%S90
COMRFSH
Function
Refresh common words
Initial State
0
Platforms
M340: No M580: No M580 Safety: No Quantum: No Momentum: No Premium: Yes Atrium: Yes
Normally set to 0, this bit is set to 1 on receiving common words from another network station.
This bit can be set to 0 by the program or the terminal to check the common words exchange cycle.
%S91
LCKASYNREQ
Function
Lock asynchronous request
Initial State
0
Platforms
M340: No M580: No M580 Safety: No Quantum: No Momentum: No Premium: Yes Atrium: Yes
When this bit is set to 1, the asynchronous communication requests processed in the monitoring task are entirely executed without interruption from the other MAST or FAST tasks, thus ensuring the data is read or written consistently.
Reminder: the request server of the monitoring task is addressed via gate 7 (X-Way).
%S92
EXCHGTIME
Function
Measurement mode of the communication function
Initial State
0
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: No Momentum: No Premium: Yes Atrium: Yes
Normally set to 0, this bit can be set to 1 by the user to set communication functions to performance measurement mode.
The communication functions’ time-out parameter (in the management table) then displays the round trip exchange time in milliseconds.
When resetting %S92 to return to the initial mode, the user application must reinitialize the value of the time-out parameter.
NOTE: The communication functions are executed with a time base of 100 ms.
%S94
SAVECURRVAL
Function
Saving adjustment values
Initial State
0
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: Yes Momentum: Yes Premium: Yes Atrium: Yes
Normally at 0, this bit can be set to 1 by the user to replace the initial values of the declared variables with a ‘Save’ attribute (e.g.: DFB variables) with the current values.
The system resets the bit %S94 to 0 when the replacement has been made.
For Modicon M340, on a %S94 rising edge, the internal RAM and the memory card content are different (%S96 = 0 and the CARDERR LED is on). On cold start, the current values are replaced by the most recent initial values only if a save to memory card function (Backup Save or %S66 rising edge) was done.
For M580 safety, it does not apply to SAFE variables. the SAFE initial values are not modifiable by the activation of this bit.
NOTE: This bit must be used with care: do not set this bit permanently to 1 and use the master task only.
When used with the TSX MFP • or TSX MCP •flash PCMCIA memory the saving adjustment values is not available.
CAUTION
APPLICATION UPLOAD NOT SUCCESSFUL
The bit %S94 must not be set to 1 during an upload.
If the bit %S94 is set to 1 then the upload may be impossible.
Failure to follow these instructions can result in injury or equipment damage.
CAUTION
LOSS OF DATA
The bit %S94 must not be used with the TSX MFP • or the TSX MCP • flash PCMCIA memory. The function of this system bit is not available with this type of memory.
Failure to follow these instructions can result in injury or equipment damage.
Bit
Symbol
%S96
BACKUPPROGOK
Function
Backup program OK
Initial State
–
Platforms
M340: Yes M580: Yes M580 Safety: Yes Quantum: No Momentum: No Premium: No Atrium: No
This bit is set to 0 or 1 by the system.
  • Set to 0 when the card is missing or unusable (bad format, unrecognized type, etc.), or the card content is inconsistent with Internal Application RAM.
  • Set to 1 when the card is correct and the application is consistent with CPU Internal Application RAM.
%S97
Function
Backup program OK
Initial State
–
Platforms
M340: No M580: Yes M580 Safety: Yes Quantum: No Momentum: Yes Premium: No Atrium: No
This bit compares the application as executed in ram versus the internal backup saved to flash. Values are:
  • 0: application backup not consistent. This state is obtained when application has been auto modified (saveparam or replace init value) and not saved using %S66.
  • 1: application backup is consistent.
Mixing the %S83 and %S84 bits
Mixing the two system bits leads to the following Hot Standby operating mode matrix.
%S83
%S84
Hybrid
Loss of last Ethernet drop
Primary CRP312 fail
Secondary CRP312 fail
Loss of optic link
0
0
No
Offline/Offline
Offline/Primary
Primary/Offline
Primary/Offline
0
0
Yes
Offline/Offline
Offline/Primary
Primary/Offline
Primary/Offline
0
1
No
Primary/Standby
Offline/Primary
Primary/Offline
Primary/Offline
0
1
Yes
Primary/Standby
Offline/Primary
Primary/Offline
Primary/Offline
1
0
No
Offline/Offline
Offline/Primary
Primary/Offline
Primary/Offline
1
0
Yes
Primary/Standby
Offline/Primary
Primary/Standby
Primary/Offline
1
1
No
Primary/Standby
Offline/Primary
Primary/Offline
Primary/Offline
1
1
Yes
Primary/Standby
Offline/Primary
Primary/Standby
Primary/Offline