SRVO-019

Verify Enable Switch Position

Hold the teach pendant with your dominant hand and squeeze the enable switch on the back to the middle position. You should feel two distinct detents - squeeze past the first click but not into the second (panic) position. The TP screen should show 'ENABLED' in the status bar at the top when properly engaged.

Never defeat or bypass the enable switch - it is a critical safety device per ANSI/RIA R15.06 standards.

Check Operating Mode

Press MENUS > System > Variables > $TP_GEN_STATE to verify TP enable status shows '2' (enabled). Also verify operating mode via MENUS > System > Variables > $OP_MODE shows '1' (T1) or '2' (T2). The enable switch only functions in teach modes, not AUTO or remote modes.

System variable $SCR.$TPENBL shows real-time enable switch status: 1=enabled, 0=disabled. Use this for quick diagnostics.

Test Enable Switch Functionality

Navigate to MENUS > I/O > TP Panel I/O and monitor signals SOP[1] (TP Enable) and SOP[2] (Deadman). With enable switch in middle position, both should show ON. Release or over-squeeze and they should turn OFF. If signals don't respond, the switch mechanism is faulty.

On R-30iA/iB, you can also check $TP_PANEL_SOP[1] and $TP_PANEL_SOP[2] variables for real-time switch status.

Verify Mode Selection

Confirm the mode switch on the operator panel is in T1 or T2 position (not AUTO). If in AUTO mode with remote TP enabled, the enable switch will not function. Check system variable $MODE_SEL for actual mode: 1=T1, 2=T2, 3=AUTO.

Perform Enable Switch Continuity Test

Navigate to MENUS > I/O > TP Panel I/O and observe SOP[1] and SOP[2] while repeatedly squeezing and releasing the enable switch. Any intermittent behavior, delayed response, or failure to change state indicates switch failure. The signals should change state crisply within 20ms of switch movement.

Enable switches typically fail after 50,000-100,000 cycles. Check maintenance logs for TP age and usage patterns.

Inspect Teach Pendant Cable

Power down the controller and inspect the TP cable for damage, especially near the pendant body and at the connector on the controller cabinet. Flex the cable while monitoring for physical damage, cuts in the jacket, or excessive wear. The enable switch signals run through pins 6 and 7 on R-30iA/iB connectors.

Always power down and lock out the controller before disconnecting or inspecting teach pendant cables to prevent electrical hazards.

Test with Spare Teach Pendant

If available, connect a known-good spare teach pendant and test enable switch functionality. If the alarm clears with the spare pendant, the original TP enable switch assembly requires replacement. The TP does not require recalibration after replacement on R-30iB controllers.

Always keep a spare TP in your facility for quick diagnostics. TP failures can halt production for hours if expedited replacement parts are unavailable.

Check TP Panel I/O Board Configuration

Navigate to MENUS > Setup > TP Panel I/O and verify the TP Panel I/O configuration matches your teach pendant model. Incorrect configuration can prevent enable signals from being recognized. For iPendant Touch, verify $TPIF_CFG.$PANEL_TYPE = 4.

After controller battery replacements, TP configuration can revert to defaults. Always verify TP settings after any backup/restore operation.

Verify UOP Configuration Settings

Navigate to MENUS > Setup > UOP and check if UOP is enabled. Review system variable $UOP.$ENABLE - if set to TRUE, check $UOP.$TP_ENABLE_MASK to verify teach pendant is not disabled for current mode. Bit masking may prevent TP enable in specific operating modes based on integrator configuration.

UOP configurations are often customized by system integrators. Always obtain and review the safety PLC ladder logic documentation for your specific cell.

Check Dual Check Safety Status

For robots with DCS option, navigate to MENUS > System > Safety > DCS Status and verify all safety chains show normal status. Check system variables $SCR.$SAFE_POS and $SCR.$SFSPD_OVR to ensure safety speed monitoring is not preventing enable recognition. DCS may require safety CPU acknowledgment before TP enable is valid.

Never modify DCS parameters without proper safety training and validation. Incorrect DCS settings can compromise robot safety systems and violate safety certification.