On this page
Asset Type
Manufacturer
Model
What This Guide Helps With
Error 321 Link Switch error (up) indicating the upper link switch is not activating, causing pump door/latch detection failure and preventing operation or infusion start.
Step-by-Step Troubleshooting
Ensure Patient Safety First
- Remove the pump from patient use if actively infusing
- Transfer infusion to another pump if needed
- Do not attempt troubleshooting on an active patient
Verify the Reported Error and Behavior
- Power on the pump and confirm Error: 321 Link Switch error (up) is displayed
- Open and close the pump door while observing behavior
- Note if the error appears at startup or during latch movement
- Determine if the error changes with door position
Inspect the Pump Door and Latch Mechanism
- Open the pump door and inspect latch arm movement
- Check for debris, dried fluid, or residue
- Look for signs of damage or misalignment
- Manually move the latch and feel for abnormal resistance or looseness
Check for Cassette or Loading Issues
- Insert a known good IV set/cassette
- Ensure cassette is fully seated
- Close the door firmly until fully latched
- Confirm proper latch engagement (audible/physical click)
Clean the Latch/Switch Area
- Use approved cleaning methods to remove debris or buildup
- Focus on latch contact points and internal switch areas
- Allow the area to fully dry before retesting
Check for Mechanical Alignment Issues
- Observe door alignment during closure
- Ensure latch fully engages without offset
- Try reseating the cassette and closing the door again
Power Cycle the Pump
- Turn the pump off and wait 10–15 seconds
- Power the pump back on
- Reattempt normal operation
Isolate the Cause
- Accessory-related: cassette not seating correctly
- Mechanical-related: latch not engaging properly
- Device-related: internal switch or sensor failure
If the Problem Persists
If Error 321 continues after all external checks, internal upper link switch or detection circuitry is likely faulty.
- Remove device from service
- Label Out of Service
- Send for repair or bench evaluation
Clinical Use Tip
Never troubleshoot on an active patient. Move the patient to a backup device before addressing this error.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Pump displaying Error 321 Link Switch error (up); unable to start infusion."
Cause
What was observed during troubleshooting.
Example:
"Upper link switch not activating; latch mechanism inspected and no external obstruction found."
Resolution
What action was taken.
Example:
"Cleaned latch area, verified cassette seating, and power cycled unit. Error persisted. Removed from service and sent for repair."
Helpful Details to Include (If Known)
- Alarm behavior
- Accessories swapped
- Power behavior
- Environmental factors
- Indicator lights
- Final device status
Final Thought
This error reflects a mechanical detection issue tied to the latch system. Always start with external inspection and loading before escalating to internal faults. Proper escalation protects both the device and patient safety.
That is successful troubleshooting.