What causes FANUC Robot alarm SYST-019?

No program selected in the controller before cycle start. PNS select did not successfully select a program. Program was deselected during a fault or reset. Auto start configuration not pointing to a valid program. Operator cleared the program selection before the cycle started.

How do I fix FANUC Robot alarm SYST-019?

1. Select a program on the teach pendant before issuing cycle start. 2. If using PNS, verify the program selection sequence from the PLC is working correctly. 3. Check auto start configuration if the robot should automatically select a program on power-up. 4. Press RESET and re-select the program.

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FANUC Robot Controller

System · Intermediate · 15-60 minutes

Alarm SYST-019

Fanuc Robot SYST-019 - Program not selected

SYST-019 occurs when the robot controller receives a cycle start command (via START button, PLC signal, or auto-start trigger) but no TP program is currently selected in the active task. This is a safety interlock preventing the robot from attempting to execute without a valid program pointer in memory.

FANUC RobotSystemIntermediate15-60 minutes

SYST-019

Fanuc Robot SYST-019 - Program not selected

Program not selected

Root Cause Summary

SYST-019 occurs when the robot controller receives a cycle start command (via START button, PLC signal, or auto-start trigger) but no TP program is currently selected in the active task. This is a safety interlock preventing the robot from attempting to execute without a valid program pointer in memory.

Safety

Always verify robot is in a safe stopped state before entering the work envelope
Use T1 mode when testing after clearing servo or motion alarms

Causes and Fixes

1
Verify current program selection status
On the teach pendant, check the top status bar. If it shows '----' or blank where the program name should appear (upper left area), no program is selected. Press SELECT on the teach pendant and navigate to the desired program from the file list.
The status bar always shows the currently selected program. If you see a program name but still get SYST-019, the program may have been deselected by a reset or fault between when you looked and when you started.
2
Select program via teach pendant menu
Press MENU → SELECT (or FCTN → SELECT on older pendants). Navigate to the program using cursor keys. Highlight the desired program and press ENTER. Verify the program name now appears in the status bar.
Ensure you are in the correct task if running a multitask system. Check the task indicator on the status bar (T1, T2, etc.).
3
Verify program is not password protected or unavailable
If the program appears grayed out or cannot be selected, check MENU → SYSTEM → Security to verify you have sufficient access level. Program protection may prevent selection. Also verify the program exists in the FROM: device shown (MD:, MC:, UD1:, etc.).
Programs on memory cards (MC:) cannot be selected if the card is removed or corrupted. Always verify the device prefix matches available storage.
4
Test cycle start with selected program
With program selected and status bar displaying program name, ensure mode switch is in appropriate position (AUTO for production, T1/T2 for testing). Press and hold START button or trigger PLC start signal. Alarm should clear and program execute.

1
Verify PNS is enabled in system configuration
Navigate to MENU → I/O → Config → User Interface (UI). Check that Program Number Selection is set to ENABLED. If disabled, PNS signals from PLC will be ignored. Also verify the PNS format (BCD or Binary) matches your PLC output configuration.
The UI configuration is in system variable $UI_CFG. You can check $UI_CFG.$PNS_ENA (TRUE/FALSE) and $UI_CFG.$PNS_FMT (BCD/BINARY) programmatically if needed.
2
Monitor PNS handshake signals in real-time
Go to MENU → I/O → UI Signals. Monitor PNSTROBE (input from PLC) and PNSACK (output from robot). Trigger a program selection from PLC and observe: PLC sets program number on UI[1-8] or UI[1-10], then pulses PNSTROBE high. Robot should pulse PNSACK high when selection succeeds. If PNSACK never goes high, selection failed.
Do not manually force UI signals while troubleshooting PNS - this can cause unpredictable program selection and safety issues.
3
Verify program number mapping table
Press SELECT on pendant, then press SHOW (F5 key). This displays the program number assignment table. Verify the program number being sent by PLC (on UI[1-8] or UI[1-10]) corresponds to an actual program in the table. Add or modify assignments if needed using the EDIT function.
Program number 0 is invalid and will cause selection failure. Valid program numbers are 1-9999. Gaps in numbering are allowed - you don't need sequential assignments.
4
Check PNS timing parameters
If handshake signals look correct but selection still fails, check system variable $UI_CFG.$PNSTB_TIM (PNSTROBE debounce time in milliseconds, default 50ms). If PLC pulse is too short, increase this value. Also verify PLC is holding PNSTROBE high long enough for robot to acknowledge (minimum 100ms recommended).
Common integration error: PLC sends PNSTROBE and CYCLE_START simultaneously. Always ensure PNSACK goes high confirming selection BEFORE sending cycle start signal. Add interlock logic in PLC.
5
Test manual PNS using force function
For diagnostic purposes only: Go to MENU → I/O → Digital → UI Signals. Set the desired program number on UI[1-8], then momentarily force PNSTROBE to ON (simulate PLC signal). Watch for PNSACK response and verify program selects. This isolates controller vs. PLC issues.
Only perform force testing with robot in T1 mode and clear of obstacles. Remove all forces after testing and return to normal PLC control.

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