SRVO-009

Verify facility air supply pressure

Check the main facility air supply gauge. Verify pressure is at least 0.5 MPa (72 PSI) minimum. Check if other equipment on the same air line is also experiencing pressure issues, indicating a facility-wide supply problem.

Before checking air connections, verify robot is in a safe position and all motion is stopped. E-stop the system before disconnecting any pneumatic lines.

Inspect pneumatic regulator and gauge

Locate the pneumatic regulator (typically mounted near the robot base or on the end effector supply manifold). Verify the regulator outlet gauge shows 0.5-0.7 MPa. Adjust regulator if needed by pulling out the adjustment knob and turning clockwise to increase pressure. Listen for air leaks while adjusting.

If the regulator gauge shows correct pressure but the alarm persists, the gauge may be reading incorrectly due to downstream blockage. Temporarily disconnect the line at the robot end to verify actual flow.

Check air filter/lubricator unit (FRL)

Inspect the filter-regulator-lubricator unit for clogged filter elements, empty lubricator reservoir, or water accumulation in the filter bowl. A clogged filter can cause significant pressure drop. Drain water from filter bowl and replace filter element if discolored or clogged.

On high-cycle applications, filter elements should be inspected monthly. A 10-15 PSI drop across the FRL unit indicates filter replacement is needed.

Inspect pneumatic lines and fittings

Trace the air supply line from the regulator to the robot tooling. Check all push-to-connect fittings, quick disconnects, and flexible hoses for leaks (use soap solution or ultrasonic leak detector). Pay special attention to connections at the robot wrist where movement causes wear. Check for kinked or damaged hoses in the cable dress-out.

Do not over-tighten compression fittings on polyurethane tubing as this can cause tube deformation and future leaks.

Verify PPABN signal state at teach pendant

From the teach pendant, navigate to MENU > I/O > Digital > IN. Scroll to find the PPABN input (typically DI[x] where x is specified in the machine builder documentation). Observe the signal state: ON = pressure OK, OFF = low pressure alarm. Compare this to actual pressure gauge reading to identify if the issue is real or signal-related.

Note the DI number for PPABN - you'll need it for further diagnostics. Common assignments are DI[13] or DI[17] but this varies by integrator.

Test pressure switch operation

Locate the pneumatic pressure switch (typically mounted on the regulator or manifold). While monitoring the PPABN input on the teach pendant I/O screen, slowly reduce air pressure using the regulator and observe when the signal changes state. It should switch OFF at the rated threshold (typically 0.4-0.5 MPa). If it doesn't switch or switches erratically, the pressure switch is faulty.

Ensure robot programs are disabled and motion is not possible during this test to prevent unexpected operation when pressure is restored.

Inspect signal wiring and connections

Check the pressure switch wiring from the switch to the robot controller. Verify connections at: 1) pressure switch terminals, 2) any intermediate junction boxes, 3) robot controller CN__ connector (check machine builder wiring diagram). Look for loose terminals, corroded connections, or damaged wire insulation. Measure continuity with a multimeter if fault is suspected.

On R-30iB controllers, check the connector extraction force - repeated teach pendant cable disconnects can loosen adjacent terminals over time.

Force PPABN signal for testing

To isolate controller vs. field wiring issues, navigate to MENU > I/O > Digital > IN, cursor to the PPABN input, press F5 [SIMULATE]. Force the signal ON. If the alarm clears, the issue is in the field wiring or pressure switch. If alarm persists, there may be a configuration issue or controller fault.

Signal forcing bypasses safety interlocks. Only use for diagnostic purposes with robot in T1 mode and operator maintaining full awareness. Disable forcing after testing.

Verify if pneumatic monitoring is required

Consult machine builder documentation or system drawings to determine if the robot system uses pneumatic end-of-arm tooling. Check if a pressure switch is physically installed on the robot. If no pneumatic devices are present, the PPABN monitoring can be disabled.

Even if the end effector is currently non-pneumatic, check if the robot is designed for future pneumatic tooling. Integrators often pre-wire the PPABN circuit for flexibility.

Access system configuration variables

From teach pendant: MENU > SYSTEM > Config. Press F1 [TYPE] and select 'All'. Scroll or search for variables containing 'PPAB' or 'PNEUMATIC'. Look for configuration variables like $MCR.$GENOVERRIDE, $SCR.$PPABNENABLE, or similar parameters that control pneumatic monitoring (exact names vary by system version and integrator setup).

Modifying system configuration requires sufficient password access level. Incorrect changes can affect robot safety systems. Document original values before making changes.