LATCH_SERVICE_STATE_FAULTED
Viewing this guide for
Applicable alarms (3)
LATCH_SERVICE_STATE_FAULTED0x001002C2ZIP_EXECUTIVE_V4_DOCK_LATCH_STATE_FAULTED
Likely outcomes — click to expand
Based on 0 missions where this alarm fired in the last
90 days
(for LATCH_SERVICE_STATE_FAULTED) as of 2026-10-13
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
is-the-dock-on-2025-30-rc2-or-earlier-a{"<small><b>Step 1</b></small><br/>Question: Is the Dock on 2025.30.rc2 or earlier..."}
is-there-an-aircraft-docked{"<small><b>Step 2</b></small><br/>Question: Is there an Aircraft docked?"}
ssh-into-dock-rm-bins-restart-with-ac["<small><b>Step 3</b></small><br/>Action: 1. SSH into the Dock. For steps, see ..."]
is-latch-state-still-faulted-after-restart{"<small><b>Step 4</b></small><br/>Question: Is the latch state still LATCH_SERVI..."}
unbuddy-aircraft-ssh-rm-bins-restart-cal["<small><b>Step 5</b></small><br/>Action: 1. Unbuddy the Aircraft from the bay ..."]
is-latch-state-still-faulted-after-calibration{"<small><b>Step 6</b></small><br/>Question: Is the latch state still LATCH_SERVI..."}
dock-may-return-to-service-after-latch-reset["<small><b>Step 7</b></small><br/>Action: The Dock may return to service."]
in-fleet-wrangler-look-at-the-docks-ala{"<small><b>Step 8</b></small><br/>Question: In Fleet Wrangler, look at the Dock’s..."}
cinch-failed-no-action["<small><b>Step 9</b></small><br/>Action: No action from this alarm, look for o..."]
zip-presence-lost-no-action["<small><b>Step 10</b></small><br/>Action: No action from this alarm, look for o..."]
calibration-encoder-drift-warning-no-ac["<small><b>Step 11</b></small><br/>Action: No action from this alarm, look for o..."]
actuator-backdrive-no-action["<small><b>Step 12</b></small><br/>Action: No action from this alarm, look for o..."]
actuator-short-circuit-escalate{{"<small><b>Step 13</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call ..."}}
actuator-open-circuit-plot-logs{"<small><b>Step 14</b></small><br/>Question: Plot logs from when the latch faulted..."}
open-circuit-power-loss-reset["<small><b>Step 15</b></small><br/>Action: The logs should look similar to the e..."]
open-circuit-no-power-loss-escalate{{"<small><b>Step 16</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call ..."}}
actuator-stalled-plot-logs{"<small><b>Step 17</b></small><br/>Question: Plot logs from when the latch faulted..."}
stalled-yes-overcurrent-check-duty-cycle["<small><b>Step 18</b></small><br/>Action: This is the dock controller H-bridge ..."]
stalled-check-commanded-duty-cycle{"<small><b>Step 19</b></small><br/>Question: Does the commanded_duty_cycle go fr..."}
stalled-duty-cycle-software-bug-reset["<small><b>Step 20</b></small><br/>Action: The plot should look similar to the e..."]
stalled-no-check-calibrating{"<small><b>Step 21</b></small><br/>Question: Was the latch_service_state transit..."}
stalled-calibrating-to-faulted-reset["<small><b>Step 22</b></small><br/>Action: It is likely that the weight of the A..."]
stalled-calibrating-is-issue-resolved{"<small><b>Step 23</b></small><br/>Question: Is the issue resolved?"}
stalled-calibrating-try-reset-two-more-times["<small><b>Step 24</b></small><br/>Action: Try to reset the latch up to two 2 ..."]
stalled-calibrating-is-issue-resolved-after-retries{"<small><b>Step 25</b></small><br/>Question: Is the issue resolved?"}
dock-may-return-to-service-after-calibrating-reset["<small><b>Step 26</b></small><br/>Action: The Dock may return to service."]
stalled-calibrating-dead-latch-rescue-escalate{{"<small><b>Step 27</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call...."}}
stalled-check-fin-hat{"<small><b>Step 28</b></small><br/>Question: Request an inspection of the Dock lat..."}
stalled-fin-hat-replace-dock["<small><b>Step 29</b></small><br/>Action: Replace the Dock. This Dock can be re..."]
stalled-fin-hat-no-escalate{{"<small><b>Step 30</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call ..."}}
unexpected-open-find-latch-state["<small><b>Step 31</b></small><br/>Action: Find when the latch state changed to ..."]
unexpected-open-retained-to-faulted{"<small><b>Step 32</b></small><br/>Question: Does the latch_service_state go fro..."}
unexpected-open-retained-check-zip-detec["<small><b>Step 33</b></small><br/>Action: 1. Check the zip_detected field at ..."]
unexpected-open-check-hall-sensor-blip{"<small><b>Step 34</b></small><br/>Question: Look at the hall_sensor_mv plot. Do..."}
unexpected-open-hall-blip-reset["<small><b>Step 35</b></small><br/>Action: The plot should look similar to the e..."]
unexpected-open-check-ac-input-voltage{"<small><b>Step 36</b></small><br/>Question: Check the ac_input_voltage plot. Do..."}
unexpected-open-ac-voltage-escalate["<small><b>Step 37</b></small><br/>Action: The plot should look similar to the e..."]
unexpected-open-final-escalate{{"<small><b>Step 38</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call ..."}}
hall-sensor-irrational-too-low-escalate{{"<small><b>Step 39</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call ..."}}
calibration-encoder-drift-critical-esca{{"<small><b>Step 40</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call ..."}}
alarm-not-listed-escalate{{"<small><b>Step 41</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call ..."}}
is-the-dock-on-2025-30-rc2-or-earlier-a -->|Yes| is-there-an-aircraft-docked
is-the-dock-on-2025-30-rc2-or-earlier-a -->|No| in-fleet-wrangler-look-at-the-docks-ala
is-there-an-aircraft-docked -->|Yes| ssh-into-dock-rm-bins-restart-with-ac
is-there-an-aircraft-docked -->|No| unbuddy-aircraft-ssh-rm-bins-restart-cal
ssh-into-dock-rm-bins-restart-with-ac --> is-latch-state-still-faulted-after-restart
is-latch-state-still-faulted-after-restart -->|Yes| in-fleet-wrangler-look-at-the-docks-ala
is-latch-state-still-faulted-after-restart -->|No| dock-may-return-to-service-after-latch-reset
unbuddy-aircraft-ssh-rm-bins-restart-cal --> is-latch-state-still-faulted-after-calibration
is-latch-state-still-faulted-after-calibration -->|Yes| in-fleet-wrangler-look-at-the-docks-ala
is-latch-state-still-faulted-after-calibration -->|No| dock-may-return-to-service-after-latch-reset
in-fleet-wrangler-look-at-the-docks-ala -->|CINCH_FAILED| cinch-failed-no-action
in-fleet-wrangler-look-at-the-docks-ala -->|ZIP_PRESENCE_LOST| zip-presence-lost-no-action
in-fleet-wrangler-look-at-the-docks-ala -->|CALIBRATION_ENCODER_DRIFT_W...| calibration-encoder-drift-warning-no-ac
in-fleet-wrangler-look-at-the-docks-ala -->|ACTUATOR_BACKDRIVE| actuator-backdrive-no-action
in-fleet-wrangler-look-at-the-docks-ala -->|ACTUATOR_SHORT_CIRCUIT| actuator-short-circuit-escalate
in-fleet-wrangler-look-at-the-docks-ala -->|ACTUATOR_OPEN_CIRCUIT| actuator-open-circuit-plot-logs
in-fleet-wrangler-look-at-the-docks-ala -->|ACTUATOR_STALLED| actuator-stalled-plot-logs
in-fleet-wrangler-look-at-the-docks-ala -->|UNEXPECTED_OPEN| unexpected-open-find-latch-state
in-fleet-wrangler-look-at-the-docks-ala -->|HALL_SENSOR_IRRATIONAL_TOO_LOW| hall-sensor-irrational-too-low-escalate
in-fleet-wrangler-look-at-the-docks-ala -->|CALIBRATION_ENCODER_DRIFT_C...| calibration-encoder-drift-critical-esca
in-fleet-wrangler-look-at-the-docks-ala -->|The alarm isn't listed / th...| alarm-not-listed-escalate
actuator-open-circuit-plot-logs -->|Yes| open-circuit-power-loss-reset
actuator-open-circuit-plot-logs -->|No| open-circuit-no-power-loss-escalate
actuator-stalled-plot-logs -->|Yes| stalled-yes-overcurrent-check-duty-cycle
actuator-stalled-plot-logs -->|No| stalled-no-check-calibrating
stalled-yes-overcurrent-check-duty-cycle --> stalled-check-commanded-duty-cycle
stalled-check-commanded-duty-cycle -->|Yes| stalled-duty-cycle-software-bug-reset
stalled-check-commanded-duty-cycle -->|No| stalled-no-check-calibrating
stalled-no-check-calibrating -->|Yes| stalled-calibrating-to-faulted-reset
stalled-no-check-calibrating -->|No| stalled-check-fin-hat
stalled-calibrating-to-faulted-reset --> stalled-calibrating-is-issue-resolved
stalled-calibrating-is-issue-resolved -->|Yes| dock-may-return-to-service-after-calibrating-reset
stalled-calibrating-is-issue-resolved -->|No| stalled-calibrating-try-reset-two-more-times
stalled-calibrating-try-reset-two-more-times --> stalled-calibrating-is-issue-resolved-after-retries
stalled-calibrating-is-issue-resolved-after-retries -->|Yes| dock-may-return-to-service-after-calibrating-reset
stalled-calibrating-is-issue-resolved-after-retries -->|No| stalled-calibrating-dead-latch-rescue-escalate
stalled-check-fin-hat -->|Yes| stalled-fin-hat-replace-dock
stalled-check-fin-hat -->|No| stalled-fin-hat-no-escalate
unexpected-open-find-latch-state --> unexpected-open-retained-to-faulted
unexpected-open-retained-to-faulted -->|Yes| unexpected-open-retained-check-zip-detec
unexpected-open-retained-to-faulted -->|No| unexpected-open-check-hall-sensor-blip
unexpected-open-retained-check-zip-detec --> unexpected-open-check-hall-sensor-blip
unexpected-open-check-hall-sensor-blip -->|Yes| unexpected-open-hall-blip-reset
unexpected-open-check-hall-sensor-blip -->|No| unexpected-open-check-ac-input-voltage
unexpected-open-check-ac-input-voltage -->|Yes| unexpected-open-ac-voltage-escalate
unexpected-open-check-ac-input-voltage -->|No| unexpected-open-final-escalate
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1 question
Is the Dock on 2025.30.rc2 or earlier AND did the
/dock.charger_status.ac_input_voltage signal drop to 0 at the time of the latch fault, indicating a recent power loss to the Dock? 2 question
Is there an Aircraft docked?
3 action
1. SSH into the Dock. For steps, see SSH into Dock.
2. Run
3. Run
4. Reference Restart Dock Latch Service to restart the latch service.
2. Run
sudo rm /application/state/latch_service_a.bin3. Run
sudo rm /application/state/latch_service_b.bin4. Reference Restart Dock Latch Service to restart the latch service.
4 question
Is the latch state still
LATCH_SERVICE_STATE_FAULTED? 5 action
1. Unbuddy the Aircraft from the bay if needed.
2. SSH into the Dock. For steps, see SSH into Dock.
3. Run
4. Run
5. Reference Restart Dock Latch Service to restart the latch service.
6. Calibrate the latch (Calibrate Dock Latch (No Aircraft in Dock)).
2. SSH into the Dock. For steps, see SSH into Dock.
3. Run
sudo rm /application/state/latch_service_a.bin4. Run
sudo rm /application/state/latch_service_b.bin5. Reference Restart Dock Latch Service to restart the latch service.
6. Calibrate the latch (Calibrate Dock Latch (No Aircraft in Dock)).
6 question
Is the latch state still
LATCH_SERVICE_STATE_FAULTED? 7 action
The Dock may return to service.
8 question
In Fleet Wrangler, look at the Dock’s Alarms view. What alarm is set?
9 action
No action from this alarm, look for other latch alarms.
10 action
No action from this alarm, look for other latch alarms.
11 action
No action from this alarm, look for other latch alarms.
12 action
No action from this alarm, look for other latch alarms.
13 escalation
Escalate to P2 Dock Hardware On Call - a latch swap is likely required.
14 question
Plot logs from when the latch faulted using the baraza template “Dock Latch Faulted.” Is there missing data that looks like the Dock could have lost power?
15 action
The logs should look similar to the examples below.
This is likely an issue from the Dock losing power. You can ignore this alarm.
1. Reset the latch to return the Dock to service (Reset Dock Latch).
2. Close the discrepancy against the Dock.
.png)
This is likely an issue from the Dock losing power. You can ignore this alarm.
1. Reset the latch to return the Dock to service (Reset Dock Latch).
2. Close the discrepancy against the Dock.
Show example
16 escalation
Escalate to P2 Dock Hardware On Call - a latch swap is likely required.
17 question
Plot logs from when the latch faulted using the baraza template “Dock Latch Faulted.” Does
/dock.latch_diagnostics.current_ma read a fairly constant ~9100mA? 18 action
This is the dock controller H-bridge shutting itself down due to overcurrent protection.
19 question
Does the
commanded_duty_cycle go from 0 directly to 100%, skipping 70%? 20 action
The plot should look similar to the examples below.
1. Looks like a software bug. You can ignore this alarm.
2. Reset the latch to return the Dock to service (Reset Dock Latch).
3. Close the discrepancy against the Dock.
.png)
1. Looks like a software bug. You can ignore this alarm.
2. Reset the latch to return the Dock to service (Reset Dock Latch).
3. Close the discrepancy against the Dock.
Show example
21 question
Was the
latch_service_state transitioning from CALIBRATING to FAULTED? 22 action
It is likely that the weight of the Aircraft was sitting on one jaw while being removed from the Dock.
- Reset the latch to return the Dock to service (Reset Dock Latch).
NOTE: Remind the operators taking the Aircraft out of the Dock to push up on the Aircraft body until the latch opens.
23 question
Is the issue resolved?
24 action
Try to reset the latch up to two (2) more times.
25 question
Is the issue resolved?
26 action
The Dock may return to service.
27 escalation
Escalate to P2 Dock Hardware On Call. You will likely need to perform a dead latch rescue - see steps 4b and 4c in the “Remove a Zip from the Dock Assembly” section of the Dock CMM.
28 question
Request an inspection of the Dock latch from below. It should not be stuck behind the lead-in. Is the fin hat stuck on the lead-in?
29 action
Replace the Dock. This Dock can be repaired by taking the lead-in off and reseating the lead-in correctly. Run a full EOL test on the Dock before returning to service.
30 escalation
Escalate to P2 Dock Hardware On Call - a latch swap is likely required.
31 action
Find when the latch state changed to
FAULTED using the baraza template “Dock Logs - Latch State”. Plot around the timestamp of the state change to FAULTED using the baraza template “Dock Logs - Latch Faulted”. 32 question
Does the
latch_service_state go from RETAINED to FAULTED? 33 action
1. Check the
- FALSE: The plot should look similar to the examples below.
This is probably a case where the latch_commander tool put the latch into a weird state and a gust of wind caused the hall sensor to read high. You can ignore this alarm.
1. Reset the latch to return the Dock to service (Reset Dock Latch).
2. Close the discrepancy against the Dock.
- TRUE: Continue to the next step.
.png)
zip_detected field at the time of latch fault. is it FALSE or TRUE?- FALSE: The plot should look similar to the examples below.
This is probably a case where the latch_commander tool put the latch into a weird state and a gust of wind caused the hall sensor to read high. You can ignore this alarm.
1. Reset the latch to return the Dock to service (Reset Dock Latch).
2. Close the discrepancy against the Dock.
- TRUE: Continue to the next step.
Show example
34 question
Look at the
hall_sensor_mv plot. Does it blip up above 1500 mV only for 1-3 data points? 35 action
The plot should look similar to the example below.
You can ignore this alarm.
1. Reset the latch to return the Dock to service (Reset Dock Latch).
2. Close the discrepancy against the Dock.
.png)
You can ignore this alarm.
1. Reset the latch to return the Dock to service (Reset Dock Latch).
2. Close the discrepancy against the Dock.
Show example
36 question
Check the
ac_input_voltage plot. Does it drop below 100V at the time of the fault and correspond to blips in hall sensor data? 37 action
The plot should look similar to the example below. Something is wrong with the power that is feeding the dock, leading to unpredictable behavior
1. Escalate to P2 Dock Hardware On Call.
1. Escalate to P2 Dock Hardware On Call.
Show example
38 escalation
Escalate to P2 Dock Hardware On Call - a latch swap is likely required.
39 escalation
Escalate to P2 Dock Hardware On Call - a latch swap is likely required.
40 escalation
Escalate to P2 Dock Hardware On Call - a latch swap is likely required.
41 escalation
Escalate to P2 Dock Hardware On Call - a latch swap is likely required.
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Latch Swap
Section titled “Latch Swap”If P2 Dock Hardware On Call recommends a latch swap:
- If there is an Aircraft in the Dock, remove it.
-
Use the Reset Latch command to remove the Aircraft from the Dock (Reset Dock Latch).
CAUTION: The RESET command will cause the latch to calibrate and open so be ready to catch the Zip when issuing this command. If the Aircraft is docked, confirm that it is supported prior to issuing this command. This command can only be sent when the latch is in a FAULTED state.
-
- Replace the latch. See the Dock CMM for remove/install procedures.
- Send the broken latch back to Alejandro Vallejo.
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