MicroLogix 1000 LED Status

Before power is applied and communication between a connected programming device is established, the only form of communication between yourself and your MicroLogix 1000 controller is through LEDs. See the tables below to interpret your LED Status.

Normal Operation

When power is connected, only the power LED turns on and remains on. This is part of the normal powerup series. When the MicroLogix 1000 controller is placed in REM Run mode, the run LED also turns on and remains on, as described below. If a force is present, the force LED is on as well.

Consult the following text references to understand the status of your MicroLogix 1000's LED indicators: N means the LED is OFF. O means the LED is ON. F means the LED is Flashing. X means the status of the LED Does Not Matter.

LED Indicator	Powered Up	In RRUN Mode
Power	On	On
Run	Off	On
Fault	Off	Off
Force	Off	N/A

Error Exists

If an error exists within the MicroLogix 1000 controller, the controller LEDs illuminate as described in the following tables.

LED Display

Error

Possible Cause

Suggested Action

Power

Run

Fault

Force

OFF

OFF

OFF

OFF

No input power, or power supply error

No line power

Verify proper line voltage and connections to the controller.

No input power, or power supply error

Power supply overload

This problem can occur occasionally if power supply is overloaded when output loading and temperature varies

LED Display

Error

Possible Cause

Suggested Action

Power

Run

Fault

Force

ON

OFF

ON

OFF

Hardware faulting

1. Processor Memory Error

2. Loosened wiring

1. Cycle unit power. Contact your local Allen-Bradley representative if the error persists.

2. Check connections to the MicroLogix 1000 controller

LED Display

Error

Possible Cause

Suggested Action

Power

Run

Fault

Force

ON

OFF

FLASH

N/A

Application

Hardware/Software Major Fault detected

1. Monitor Status File Word S:6 for major error code.

2. Remove the hardware or software condition causing the fault.

3. Press F10 to clear the fault.

4. Attempt a MicroLogix 1000 controller REM Run mode entry. If unsuccessful, repeat recommended action steps above.

MicroLogix 1000 Controller Error Recovery Schematic

Refer to the following error recovery schematic to help you diagnose software and hardware problems in the MicroLogix 1000 controller. The schematic provides common questions you might ask to help troubleshoot the system.

Is the error hardware related?
1. If NO, (1) Identify the error code and description, (2) Clear fault using either function key F9 or F10, (3) Place the MicroLogix 1000 controller in REM PROGram mode, (4) Correct the condition using the fault, (5) Return controller to REM RUN or any of the REM tTest modes, and (F) Test and ensure system operation.
2. If YES, check the wire connections.
  1. Are the wire connections in the MicroLogix 1000 tight?
    1. If NO, (1) Tighten wire connections, and (F). (2) Tighten wire connections: (P) does the controller have power supplied?
      1. If NO, (C) Check Power.
      2. f YES, refer to "When An Error Exists" section, tables 1-2 above.
    2. If YES, is the Power LED on?
      1. If NO, (P).
      2. If YES, Is the Power LED on constantly?
        
        If YES, (F).
        
        If NO, Is the Fault LED on?
        
        If YES, refer to "When An Error Exists" section, tables 1-2 above.
        
        If NO, is an input or output LED showing proper status?
        
        If YES, (F).
        
        If NO, refer to "When An Error Exists" section, table 3 above.

Identifying MicroLogix 1000 Faults

While a program is executing, a fault may occur within the operating system or your program. When a fault occurs, you have several ways to determine what the fault is and how to correct it. This section describes how to clear faults and gives a list of possible advisory messages with recommended corrective actions.

Automatically Clearing Faults

You can automatically clear a fault when cycling power to the MicroLogix 1000 controller by setting either one or both of the following status bits in the status file:

Fault Override at Powerup bit (S:1/8)
Run Always bit (S:1/12) CAUTION: Clearing a fault using the Run Always bit (S:1/12) causes the MicroLogix 1000 controller to immediately begin the REM Run mode. Ensure you fully understand the use of this bit before incorporating it into your program.

Note: You can declare your own application-specific major fault by designating your own unique value to S:6 and then setting bit S:1/13 to prevent reusing system defined codes. The recommended values for user defined faults is FF0 to FF0F

Manually Clearing Faults Using the Fault Routine

The occurrence of recoverable or non-recoverable user faults causes file 3 to be executed. If the fault is recoverable, the sub-routine can be used to correct the problem and clear the fault bit S:1/13. The MicroLogix 1000 controller then continues in the REM Run mode. The subroutine does not execute for non-user faults.

Fault Messages

This sections describes fault messages that can occur during operation of the MicroLogix 1000 programmable controllers. Each table lists the error code description, the probable cause, and the recommended action to solve the error.

Error Code (Hex)	Advisory Message	Description	Recommended Action to Solve
0001	DEFAULT PROGRAM LOADED	The default program is loaded to the computer memory. This occurs on power-up if the power down occurred during a download, or if the user program is corrupt at power up, the default program is loaded.	Re-download the program and enter the REM Run mode.
0002	UNEXPECTED RESET	The controller was unexpectedly reset due to a noisy evnironmentt or internal hardware failure. If the user program downloaded to the controller is valid, the initial data downloaded with the program is used. The Retentive Data Lost Bit (S:5/8) is set. If the user program is invalid, the default program is loaded.	Refer to proper grounding guidelines.
0003	EEPROM MEMORY IS CORRUPT	While power cycling to your MicroLogix 1000 controller, a noise problem may have occurred. Your program may be valid, but retentive data will be lost.	Try cycling power again.
0004	RUNTIME MEMORY INTEGRITY ERROR	During the time the MicroLogix 1000 was in RUN mode or any test mode, the ROM or RAM became corrupt. If the user program is valid, the program and initial data downloaded to the controller is used and the Retentive Data Lost Bit (S:5/8) is set. If the user program is invalid, error 0003 takes place.	Cycle power on your MicroLogix 1000 unit. Download your program and reinitialize any necessary data. Start up your system.
0005	RETENTIVE DATA HAS BEEN LOST	Data files (input, output, timer, counter, integer, binary, control, and status) are corrupt.	Cycle the power on your MicroLogix 1000 unit. Download your program, and reinitialize any necessary data. Start your system.
0008	FATAL INTERNAL SOFTWARE ERROR	The MicroLogix 1000 controller software has detected an invalid condition within the hardware or software after completing power-up processing (once the first 2 seconds of operation have been completed).	Cycle the power on your unit. Download your program and reinitialize any necessary data. Start your system.
0009	FATAL INTERNAL HARDWARE ERROR	The MicroLogix 1000 controller software has detected an invalid condition within the hardware during start-up processing (once the first 2 seconds of operation have been completed).	Cycle the power on your unit. Download your program and reinitialize any necessary data. Start your system.
0010	INCOMPATIBLE PROCESSOR	The program downloaded is not configured for the MicroLogix 1000 controller.	If you want to use a micro controller with the program, configure your controller with your programming software. (choose Bul. 1761).
0016	STARTUP PROTECTION AFTER POWER LOSS S:1/9 IS SET	The system powered up in the REM Run mode. Bit S:1/13 is set and the user-fault routine is run before beginning the first scan of the program.	Either reset bit S:1/9 if this is consistent with your application requirements, and change the mode back to REM Run, or clear S:1/13, the major fault bit.
0018	USER PROGRAM IS INCOMPATIBLE WITH OPERATING SYSTEM	An incompatible program was downloaded. Either the program does not have the correct number of files, or it does not have the correct size data files. The default program is downloaded.	Check the configuration and make sure the correct processor is selected. If you want to use a MicroLogix 1000 with the program, reconfigure your controller with your programming software. (choose Bul. 1761).
0020	MINOR EFFOR AT END OF SCAN, SEE S:5	A minor fault bit (0-7) in S:5 was set at the end of the scan.	Enter the status file display and clear the fault, then return to the REM Run mode.
0022	WATCHDOG TIMER EXPIRED, SEE S:3	The program scan time exceeded the watchdog timeout value (S:3H)	Ensure the program is caught in a loop and correct the problem, and increase the watchdog timeout value in the status file.
0024	INVALID STI INTERRUPT SETPOINT, SEE S:30	An invalid STI interval exists (not between 0 and 255).	Set the STI interval between the values of 0 and 255.
0025	TOO MANY JSRs IN STI SUBROUTINE	There are more than 3 subroutines nested in the STI subroutine (file 5)	Correct the user program to meet the requirements and restrictions for the JSR instruction. Reload the program and enter the REM Run mode.
0027	TOO MANY JSRs IN FAULT SUBROUTINE	There are more than 3 subroutings nested in the fault routine (file 3).	Correct the user program to meet the requirements and restrictions for the JSR instruction. Reload the program and enter the REM Run mode.
002A	iNDEXED ADDRESS TOO LARGE FOR FILE	The program is referencing through indexed addressing an element beyond a file boundary.	Correct the user program so that it does not go beyond file boundaries.
002B	TOO MANY JSRs IN HSC	There are more than 3 subroutines nested in the high-speed counter routine (file 4).	Correct the user program to meet the requirements and restrictions for the JSR instruction. Reload the program and enter the REM Run mode.
0030	SUBROUTINE NESTING EXCEEDS LIMIT OF 8	There are more than 8 subroutines nested in the main program file (file 2).	Correct the user program to meet the requirements and restrictions for the main program file. Reload the program and enter the REM Run mode.
0031	UNSUPPORTED INSTRUCTION DETECTED	The program contains an instruction or instructions that are not supported by the micro controller. For example, SVC or PID.	Modify the program so that all instructions are supported by the MicroLogix 1000 controller. Reload the program and enter the REM Run mode.
0032	SQO/SQC CROSSED DATA FILE BOUNDARIES	A sequencer instruction length/position parameter points past the end of a data file.	Correct the program to make sure that the length and position parameters do not point past the data file. Reload the program and begin REM Run mode.
0033	BSL/BSR/FFL/FFU/LFL/FLU CROSSED DATA FILE BOUNDARIES	The length parameter of a BSL, BSR, FFL, FFU, LFL, or LFU instruction points past the end of a data file.	Correct the program to ensure that the length parameter does not point past the data file. Reload the program and enter the REM Run mode.
0034	NEGATIVE VALUE IN TIMER PRESET OR ACCUMULATOR	A negative value was entered to a timer preset or accumulator	If the program is moving values to the accumulated or preset word of a timer, ensure these values are positive. Reload the program and enter the REM Run mode.
0035	ILLEGAL INSTRUCTION (TND) IN INTERRUPT FILE	The program contains a Temporary End (TND) instruction in file 3, 4, or 5 when it is being used as an interrupt subroutine.	Correct the program. Reload the program and enter the REM Run mode.
0037	INVALID PRESETS LOADED TO HIGH-SPEED COUNTER	Either a zero (0) or a negative high preset was entered to counter (C5:0) when the HSC was an Up counter or the high preset was lower than or equal to the low preset when the HSC was a Bidirectional counter.	Check to make sure the presets are valid. Correct the program, reload, and enter the REM Run mode.
0038	SUBROUTINE RETURN INSTRUCTION (RET) IN PROGRAM FILE 2)	A RET instruction is int he main program file (file 2).	Remove the RET instruction. Reload the program and enter the REM Run mode.
0040	OUTPUT VERIFY WRITE FAILURE	When ourputs were written and read back by the MicroLogix 1000 controller, the read failed. This may have been caused by noise.	Refer to proper grounding guidelines. Start your system.
0041***	EXTRA OUTPUT BIT(S) TURNED ON	An extra output bit was set when the Extra Output Select (S:0/8) bit in the status file was reset. For 16-point controllers this includes bits 6-15. For 32-point controllers this includes bits 12-15	Set S:0/8 or change your application to prevent these bits from being turned on. Correct the program, reload, and enter the REM Run mode.

***Valid for Series A-C discrete only.

Repair Your MicroLogix 1000 Controller

Here at DO Supply, we offer repair services for your Allen-Bradley products, such as the Allen-Bradley MicroLogix 1000 Controller. Please select the Repairs tab for more information or to request a quote.

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