Bit Location

Nickname

Type

Description

ST0

$FirstScan

Status (read-only)

will be ON for the duration of the first controller scan after a STOP mode -to- RUN mode transition

ST1

$On

Status (read-only)

Always ON

ST2

$Off

Status (read-only)

Always OFF

ST3

$1Minute

Status (read-only)

while the controller is in RUN mode this bit location will be set ON once a minute with a 50% duty cycle, that is, it will be ON for 30 seconds then OFF for 30 seconds

ST4

$1Second

Status (read-only)

while the controller is in RUN mode this bit location will be set ON once a second with a 50% duty cycle, that is, it will be ON for 1/2 second then OFF for 1/2 second

ST5

$100ms

Status (read-only)

while the controller is in RUN mode this bit location will be set ON once every 100ms with a 50% duty cycle, that is, it will be ON for 50 milliseconds then OFF for 50 milliseconds

ST6

$50ms

Status (read-only)

while the controller is in RUN mode this bit location will be set ON once every 50ms with a 50% duty cycle, that is, it will be ON for 25 milliseconds then OFF for 25 milliseconds

ST7

$ScanToggle

Status (read-only)

will be ON for alternate controller scans

ST8

$LastScan

Status (read-only)

will be ON for the duration of the last controller scan before a RUN mode -to- STOP mode transition

ST10

$HasErrors

Status (read-only)

will be ON any time the controller is reporting any runtime errors

ST11

$HasWarnings

Status (read-only)

will be ON any time the controller is reporting any runtime warnings

ST12

$HasInfo

Status (read-only)

will be ON any time the controller is reporting any runtime informational messages

ST13

$WatchdogReboot

Status ((read-only)

will be ON after a Hardware Watchdog Reboot has occurred
Click this link for more information on Configuring the Hardware Watchdog Timer

ST14

$ModuleFailed

Status (read-only)

will be ON when any installed module fails validation, which generally means that its module ID doesn’t match the module ID discovered at power up

ST21

$InhPgmUpdate

Configuration (read/write)

is set to ON to prevent program from being updated

ST23

$TimeSynced

Status (read-only)

will be ON if the TimeSync operation is successful.
Click this link for more information on using TimeSync.

ST24

$HwWatchdogMode

Configuration (read/write)

specifies the action to take in the event of a Hardware Watchdog Timeout
Click this link for more information on Configuring the Hardware Watchdog Timer

ST25

$DisableHwWdog

Configuration (read/write)

is set ON to disable the Hardware Watchdog Timer
Click this link for more information on Configuring the Hardware Watchdog Timer

ST33

$EnableDebug

Configuration (read/write)

is set ON by the Debug View to put the controller in debug mode

ST34

$EnablePowerFlow

Configuration (read/write)

reserved

ST35

$EnableNScan

Configuration (read/write)

is set ON by the Debug View to put the controller into N-Scan Mode

ST36

$EnableMsgDump

Configuration (read/write)

is set ON to send all ERR and MSG values to Do-more Logger, see the Send Email (EMAIL) Instruction.

ST37

$DisableSwWdog

Configuration (read/write)

is set ON to disable the software watchdog timer

ST128

$WatchdogTimeout

Status (read-only)

will be ON when a software watchdog occurs
Click this link for more information on Configuring the Hardware Watchdog Timer

ST129

$IndexError

Status (read-only)

will be ON when an array reference is out of range

ST131

$InvalidInstr

Status (read-only)

will be ON if an invalid instruction was downloaded to controller. User generally should never see this.

ST132

$OutOfRange

Status (read-only)

will be ON when a parameter that isn’t an index error, or an overflow, or a divide-by-zero is out of range.

ST133

$Overflow

Status (read-only)

will be ON when certain math operators -for example POW, INC, DEC - overflow

ST134

$InstIOChanged

Status (read-only)

will be ON at power-up when the installed I/O has changed

ST135

$IOConfigError

Status (read-only)

will be ON when there is an error in the manual I/O configuration

ST136

$IOMapError

Status (read-only)

will be ON when there is an error in the manual I/O map

ST137

$LoopTuning

Status (read-only)

will be ON while a PID loop is being AutoTuned

ST138

$MathStackOverflw

Status (read-only)

will be ON when a math operation has caused a stack overflow

ST139

$FileSystemError

Status (read-only)

reserved

ST140

$BufferOverflow

Status (read-only)

will be ON if the result of a string operation is larger than the string element can hold

ST141

$DivideByZero

Status (read-only)

will be ON when a math operation has a divide by zero operation

ST142

$DriverLoadError

Status (read-only)

will be ON if any device driver failed to load

ST143

$DriverError

Status (read-only)

will be ON if any device is reporting a runtime error, use the Device List to see the specific device in error

ST144

$SystemStopped

Status (read-only)

will be ON when a Switch to Program Mode (STOP) instruction has executed and put the controller in Stop mode

ST145

$QueuesFlushed

Status (read-only)

will be ON when Ethernet queues were forcibly cleared, possibly due to an open Ethernet device which isn’t being serviced

ST146

$CommStackOverrn

Status (read-only)

will be ON when the Ethernet stack was unable to allocate a packet buffer for an incoming packet.

ST147

$InstrTerminated

Status (read-only)

will be ON when a Device instruction was terminated before normal completion.

ST148

$CriticalIOError

Status (read-only)

will be ON when one or more modules failed to verify for longer than the verify filter time, and the system is in a permanent I/O shutdown. Power cycle or Re-Initialize I/O required to return to RUN mode.

ST149

$BatteryLow

Status (read-only)

will be ON if the battery voltage is below the minimum threshold, see the help section on Battery Backup for more information

ST150

$LoginLockedOut

Status (read-only)

will be ON when PLC isn’t accepting session passwords due to excessive password failures. See the help topic for Failed Login Attempts.

ST151

$IndexRealigned

Status (read-only)

will be ON if the controller adjusted a misaligned array index. Occurs when incorrectly indexing memory cast to a larger size...as in X[V0]:B, where V0 isn’t 0, 8, 16, etc.

ST152

$IOError

Status (read-only)

will be ON an I/O Master is in a warning state, this can go from ON to OFF as module issues arise and are resolved

ST192

$PgmSwitchActive

Status (read-only)

will be ON when system is swapping program buffers during run mode program update

ST193

$CurPgmBuffer

Status (read-only)

Indicates active program buffer. Toggles when new program is downloaded

ST194

$SysConfigUpdate

Status (read-only)

will be ON when system is updating system configuration

ST200

$PgmROMUpdate

Status (read-only)

will be ON when system is writing to program ROM

ST201

$SysCfgROMUpdate

Status (read-only)

will be ON when system is writing to system configuration ROM

ST202

$DocROMUpdate

Status (read-only)

will be ON when system is writing to documentation ROM

ST203

$SysSetROMUpdate

Status (read-only)

will be ON when system is writing to systems settings ROM

ST204

$UserROMUpdate

Status (read-only)

ON when system is writing to user ROM

ST768

$SummerTime

Configuration (read/write)

is set ON to add one hour to $LocalTime to account for Daylight Savings Time

Numeric Location

Nickname

Type

Description

DST0

$ScanCounter

Status (read-only)

contains the number of controller scans since the last STOP mode to RUN mode transition

DST1

$ScanTime

Status (read-only)

contains a filtered average of the $ElapsedTicks

DST2

$MinScanTime

Status (read-only)

contains the length of time (in microseconds) of the shortest controller scan since the last STOP mode to RUN mode transition

DST3

$MaxScanTime

Status (read-only)

contains the length of time (in microseconds) of the longest controller scan since the last STOP mode to RUN mode transition

DST4

$ElapsedTicks

Status (read-only)

contains the number of microseconds for the last scan

DST5

$Errors

Status (read-only)

compilation of bit flags from (ST128...159) which are considered to be errors.

Currently contains the following: WATCHDOGTIMEOUT, MEMORYERROR, IOCONFIGERROR, IOMAPERROR, MATHSTACKOVERFLOW, STOPPED, COMM_STACK_OVERRUN, and PERMIOFAILURE

DST6

$Warnings

Status (read-only)

compilation of bit flags from (ST128...159) which are considered to be warnings.

Currently contains the following: INDEXERROR, OUTOFRANGE, INVALIDINSTRUCTION, OVERFLOW, FILESYSERROR,, BUFFEROVERFLOW, DIVIDEBYZERO, DRIVERLOADERROR, DRIVERERROR, QUEUES_FLUSHED, BATTERYLOW

DST7

$Info

Status (read-only)

compilation of bit flags from (ST128...159) which are considered to be info.

Currently contains the following: INSTALLEDIOCHANGED, LOOPTUNING, and LOGINLOCKEDOUT

DST8

$InvalidInstrAddr

Status (read-only)

Contains address of invalid instruction on failed program validation
 

-1 = no invalid instruction address

DST10

$PLCMode

Status (read-only)

contains a value that reflects the current operational mode of the controller, 2 = STOP mode, 3  = RUN mode

DST11

$PLCStatus

Status (read-only)

Contains the PSTAT_XXX bits from ST192-223.

DST12

$FirmwareRev

Status (read-only)

the revision number of the controller's firmware in the form MMmmbbbb

DST13

$DmRev

Status (read-only)

the revision number of the controller's Do-more library in the form MMmmbbbb

DST14

$HardwareRev

Status (read-only)

the revision number of the controller's PWB n the form 0000MMaa

DST15

$BooterRev

Status (read-only)

the revision number of the controller's boot loader in the form MMmmbbbb

DST16

$FPGARev

Status (read-only)

the revision number of the controller's FPGA code in the form MMMMmmmm

DST17

$NodeNumber

Status (read-only)

the Node Number assigned to the controller

DST18

$IPAddress

Status (read-only)

the IP Address assigned to the controller

DST19

$NetMask

Status (read-only)

The Subnet Mask assigned to the controller

DST20

$Gateway

Status (read-only)

the Gateway IP Address assigned to the controller

DST21

$UTC

Status (read-only)

contains the current UTC value (the number of seconds that have elapsed since Jan, 1 1970)

DST22

$LocalTime

Status (read-only)

the current time calculated from the UTC value after adjustments for Time Zone and Daylight Savings

DST23

$WatchdogTimeVal

Status (read-only)

contains the maximum number of milliseconds to allow for a single controller scan

DST26

$IOVerifyTimeout

Status (read-only)

contains the minimum amount of time for a module to fail verification before a permanent IO failure shutdown

DST27

$IOVerifyLastTO

Status (read-only)

contains the amount of time accrued during the last failure verification

DST28

$IOMasterErrors

Status (read-only)

contains one bit per I/O Master, that bit will be ON if that I/O Master is reporting a Module Error, can go from ON to OFF as module errors arise and are resolved.

DST30

$LastError1

Status (read-only)

contains the code of the last controller error

DST31

$LastErrorAddr1

Status (read-only)

contains the address of the last controller error

DST32

$LastError2

Status (read-only)

contains the code of the next to last controller error

DST33

$LastErrorAddr2

Status (read-only)

contains the address of the next to last controller error

DST34

$LastError3

Status (read-only)

contains the code of the next to next to last controller error

DST35

$LastErrorAddr3

Status (read-only)

contains the address of the next to next to last controller error

DST36

$LastError4

Status (read-only)

contains the code of the next to next to next to last controller error

DST37

$LastErrorAddr4

Status (read-only)

contains the address of the next to next to next to last controller error

DST38

$LastProtoError

Status (read-only)

contains the error response value from last protocol-based instruction (MRX, MWX, DLRX, DLWX, etc. )

DST39

$InhibitErrors

Configuration (read/write)

Set bits of errors which should not result in fatal shutdown of the controller.

DST40

$EthDroppedPckts

Status (read-only)

contains the number of Ethernet packets that have been lost since the last power-cycle

DST41

$EthStoppedIntr

Status (read-only)

contains the number of times the Ethernet interrupt was shut off due to excessive network traffic.

DST42

$EthSendErrors

Status (read-only)

contains the number of Ethernet send errors that have occurred since the last power-cycle

DST43

$EthPktsReceived

Status (read-only)

contains the total number of Ethernet packets that have been received since the last power-cycle

DST44

$EthPktsSent

Status (read-only)

contains the total number of Ethernet packets that have been sent since the last power-cycle

DST45

$TuneDeadBand

Configuration (read/write)

deadband value used the by the PID Autotune process

DST46

$TuneSampleTime

Configuration (read/write)

sample time value used the by the PID Autotune process

DST47

$TuneMinPVChange

Configuration (read/write)

Minimum PV Change value used the by the PID Autotune process

DST48

$TuneOutputBump

Configuration (read/write)

Output bump value used the by the PID Autotune process

DST384

$TimeZone

Configuration (read/write)

contains the number of seconds to apply to the UTC value for the current location of the controller

DST385

$WatchdogReboots

Status (read-only)

the number of software watchdog reboots that have occurred since the last power-cycle All values from DST384 up are retentive...not limited to power cycle.

DST386

$FailedLogonCounts

Status (read-only)

the number of login attempts that have failed

DST509

$ProbeAddr

Status (read-only)

use by the Debug View

DST510

$NScan

Status (read-only)

use by the Debug View

Numeric Location

Nickname

Type

Description

SDT0

$Now

Status (read-only)

the current calculated time (UTC with time zone and summertime adjustments applied)

SDT1

$SysShutdown

Status (read-only)

the date and time of the last system power-down

SDT2

$SysStartup

Status (read-only)

the date and time of the last system power-up