MicroLogix 1100 (1763) fault codes: S:6 table (0001, 0012, 0020, 0022), FAULT LED, 1F, clearing, back to RUN

On a MicroLogix 1100 (Bulletin 1763) a fault shows first on the FAULT indicator on top of the controller: flashing red means an application fault, steady red means the controller hardware has faulted (1763-UM001G-EN-P, p. 133). The code is on the Fault Code screen of the built-in LCD, and that screen does not open by itself: only the FAULT indicator flashes, so you have to go to it (p. 99). The user manual does not list what each major error code means. It sends you to the instruction set reference manual 1763-RM001 and to the RSLogix 500 online help (pp. 100, 135, 139). The full S:6 error code table below comes from that reference manual, 1763-RM001D-EN-P, appendix C (pp. 492–498). For the other MicroLogix families, see MicroLogix 1400 fault codes and MicroLogix 1500 fault codes.

Controller status indicators

In normal operation POWER and RUN are on (p. 135).

Indicators on the LCD

The MicroLogix 1100 LCD has five indicators at the top left; a solid rectangle means on (pp. 53, 134).

On the I/O Status screen (10 inputs, 6 outputs), inputs show terminal status and outputs show logic status (pp. 76, 134).

What the indicator pattern tells you

Reading the fault code on the LCD

1. On the Main Menu, select "Advance Set" with the Up and Down keys and press OK.
2. Select "Fault Code" and press OK.
3. The screen shows "Major Error Code=" and the code; "0000h" means no fault. Press ESC to go back (pp. 99–100).

On the same "Advance Set" menu, "System Info" shows the catalog number, the OS firmware revision and the boot firmware revision (pp. 98–99).

Codes and messages the user manual names

The S:6 table in 1763-RM001D has no 001F row: it goes from 001A to 0020 (p. 494). UM001G calls 1Fh a user-defined fault code (p. 107), and RM001D recommends FF00 to FF0F for faults you define yourself (p. 491).

With OS Series A FRN 1, 2 and 3 on the RSLinx Classic EtherNet/IP driver, change the RSLinx "Configure CIP Option" to prevent an ownership fault: one messaging connection per PLC, retry interval 8 seconds instead of 1.25 (p. 107).

S:6 major error codes (1763-RM001D)

On a major error the controller sets S:1/13 (Major Error Halted) and writes the code to word S:6. It then turns all outputs off and flashes FAULT, or runs the user fault routine if one is set up (RM001D pp. 472, 479). Read the code on the LCD or in the status file (p. 499).

The class column follows the manual (p. 262). Recoverable: logic in the user fault routine can clear the fault. Non-recoverable: the routine runs but the fault cannot be cleared. Non-user: program execution stops and the routine does not run.

In codes starting with xx, xx is the expansion module number; xx = 00 means the fault cannot be traced to one module. For xx89, xx8A, xx8B and xx8C, xx is the position of the last correctly configured expansion module plus one (p. 498).

When bit S:5/15 (ASCII string manipulation error) is set, 1F39 is written to S:6 (p. 479).

Battery (1763-BA) and BAT. LO

• The replacement battery is 1763-BA (pp. 23, 129); one sentence on p. 22 still names 1747-BA.
• BAT. LO solid means the battery wire connector is disconnected, or the battery will fail within 2 weeks (p. 22). The controller is designed to run for up to 2 weeks from the moment the indicator first turns on; Rockwell recommends replacing the battery at once (p. 129).
• Program and data are nonvolatile (p. 12). Keep the battery connected if you use the real-time clock or need to keep the program in memory for a long time without power (p. 22).
• Bit RTC:0/BL = 1 also means battery low. If power is removed while the battery is low, RTC data is lost (pp. 101–102).

Memory module (1763-MM1)

• 128 KB; a backup of the program and data that also carries programs between controllers; it does not add memory (pp. 12, 101). It holds one user program at a time (p. 102).
• Program Compare: with bit S:2/9 set, the controller will not enter run or test mode if the program in the module does not match the program in the controller (p. 102). RM001D shows this as code 0017 (p. 494).
• It can be inserted or removed at any time except during a data transaction. A module inserted while the controller is executing is recognized only after a power cycle or in a non-executing mode (program, suspend or fault). Write protection cannot be removed once set (p. 103).
• In RSLogix 500: "Comms" > "EEPROM" > "Load from EEPROM" or "Store to EEPROM" (p. 103).

Serial and Ethernet checks

• Channel 0 defaults: DF1 full-duplex, 19.2 Kbps, no parity, node 1, CRC. They apply at first power-up, after an OS upgrade, or when DCOMM is on (p. 51). "Advance Set" > "DCOMM Cfg" > "Enable" switches Channel 0 to them (pp. 52–54).
• Ethernet address: "Advance Set" > "ENET Cfg" shows only the MAC address until an IP address is assigned (pp. 95–96). BOOTP is enabled and the IP address is 0 (undefined) by default (pp. 159–160). The manual requires a fixed IP address, not a dynamically assigned one (p. 162).
• Link and speed: if both the switch and the controller port are forced to full duplex (10 or 100 Mbps), the link does not establish. Use auto negotiation on both, or force only the controller port and leave the switch on auto negotiation (p. 157). Cable length to the switch is at most 100 m (p. 157).
• Messaging: at most 16 outgoing and 16 incoming connections (p. 158). The embedded web server shows module, TCP/IP and diagnostic information; see 1763-UM002 (pp. 14, 163).

Checks, step by step

1. Record first: indicators, the Fault Code value, System Info.
2. Hardware branch (Figure 90, p. 136): check that the wire connections are tight and the controller has power.
3. FAULT flashing: identify the code and look it up in the S:6 table, clear the fault, correct the condition causing it, return to RUN or a REM test mode, then test and verify (p. 136).
4. Will not go to RUN with a memory module fitted: check Program Compare, S:2/9 (p. 102); the code is 0017 (RM001D p. 494).
5. Code starting with xx (xx71 to xx8C): read xx as the expansion module number; 00 means no single module; for xx89 to xx8C it is the last correctly configured module plus one (RM001D p. 498).
6. Fault routine set in S:29 but it did not run: check the class; it never runs for a non-user fault (RM001D p. 262).
7. Inputs do not match the field: compare the I/O Status screen with the field device (pp. 76, 136).
8. Expansion I/O: up to four 1762 modules. Remove power before inserting or removing one; an arc can send an erroneous signal and fault the controller (pp. 12, 28). On a fault, 1762 analog outputs reset to zero (p. 137).

Clearing the fault and returning to RUN

The user manual lists "clear the fault" as a step of its recovery model but does not describe the method (pp. 135–136); RM001D appendix C does. Return to RUN only after the condition causing the fault is corrected. Before that, make sure the machine is safe to move, because outputs will follow the program logic again; follow the plant's permit and lockout rules.

• Power cycle with S:1/8: with Fault Override at Power-Up (S:1/8) set, cycling power clears the fault, and the controller clears S:1/13 at power-up (RM001D pp. 470, 491).
• Back to RUN at every power cycle: set S:1/8 and S:1/12 (Power-Up Mode Behavior); the appendix list prints them as S2:1/8 and S2:1/12. If the fault condition is still there, the controller faults again (p. 491). With S:1/12 = 1 (Run) the power-up mode depends on the mode switch and S:1/13 only; with 0 (Last State) it also depends on the mode at the last power-down. To reach Run after a fault, S:1/8 must be set too (p. 471).
• User fault routine: create a subroutine in program file 3 to 255 and enter its number in S:29 (p. 262). It runs for recoverable and non-recoverable faults, not for non-user faults. For a recoverable fault it can fix the cause and clear S:1/13, and the controller carries on in Run or test mode (pp. 262, 492).
• Startup protection, S:1/9: when the controller powers up in RUN or REM RUN, the routine runs before the first scan, and S:6 holds 0016 while it runs. If it does not clear S:1/13, the controller faults and stays out of an executing mode (p. 470).
• From the programming software: for 0020 the manual says to clear the fault in the status file display, then enter Run (p. 494).
• Mode switch at RUN: if S:1/13 is set at power-up, the controller comes up in "Run w/Fault", with outputs reset and the program not executing; the controller enters Run as soon as S:1/13 is cleared (p. 472). Clearing S:1/13 with the switch at RUN puts the controller in RUN at once (p. 473).
• Own fault codes: write a value to S:6 and set S:1/13; RM001D recommends FF00 to FF0F (p. 491).

The user manual adds these mode settings:

• "Mode Switch" on the LCD Main Menu sets PROGRAM, REMOTE or RUN (pp. 88–90).
• At power-up, holding OK for 5 seconds forces RUN and holding ESC for 5 seconds forces PROG; output status may change (p. 89).
• With the LCD mode switch at RUN, online editing is not available (p. 109).

OS reload: connect Channel 0 to the computer with a 1761-CBL-PM02 cable, turn DCOMM on and set Program mode (p. 143). DMK firmware needs ControlFLASH 13.00 or later (p. 141). Installing an OS deletes the user program, so have a backup to download afterwards (p. 141). After a good transfer, RUN, FORCE and FAULT stay on for five seconds and the controller resets (p. 144).

When it is hardware

• POWER and FAULT stay on steady after checking connections and cycling power: contact Rockwell (p. 135).
• A 1762 analog module whose status LED stays off after a power cycle: replace the module (p. 137).
• Channel 0 was connected to a MicroLogix 1000, 1200 or 1500, or a 1747-DPS1, with a 1761-CBL-AM00 cable: the manual warns this damages Channel 0 or the controller (p. 13).

Lifecycle and replacement

TDL's end-of-life pages show all four 1763 controllers as discontinued from 30/04/2022, with the Micro850 replacements proposed in Rockwell's migration document 2080-RM002D: 1763-L16AWA → 2080-L50E-24AWB, 1763-L16BBB → 2080-L50E-24QBB, 1763-L16BWA and 1763-L16DWD → 2080-L50E-24QWB. Each page lists what else to add, for example 2080-IF2 if the analog inputs are used. For the new controller, see Micro800 fault codes.

What to record before calling for support

Rockwell asks for the controller type, series letter, revision letter and firmware (FRN) number, the indicator status and the controller error codes (p. 139). RM001D adds that the OS FRN is also in status word S:59 (p. 499). Also note whether a memory module is fitted and when the fault appears. For an engineer on site: breakdown support.