NWD Buffer, Robot Delay, and Position Delay — Focus Sync Timing Settings¶
Networking / InTime Resolved All rigs
Summary¶
Three related settings compensate for timing differences between the robot motion system and lens/accessory control:
- NWD buffer (Network Direct buffer) — affects how focus data is synchronised over the network
- Robot Delay — compensates for the communications lag between the EtherCAT robot loop and the Ethernet accessory loop (~4 ms offset)
- Position Delay — the current recommended setting for Bolt X / Yaskawa focus timing (previously handled by NWD buffer)
Getting these wrong produces focus that runs ahead of or behind the robot motion, most visible on fast moves or when target tracking.
Symptoms¶
Focus runs ahead of or behind the expected position relative to robot motion, especially during: - Fast moves - Target tracking - High-speed camera work requiring repeatable focus
Settings by Robot Type¶
| Robot | NWD Buffer | Robot Delay | Position Delay | Notes |
|---|---|---|---|---|
| Bolt (EtherCAT / Staubli), MRMC Focus/Zoom motors | 1 | 0.7 | 0 | Official relation quoted for MRMC Focus/Zoom motors on Bolt |
| Bolt (EtherCAT / Staubli), older timing note | 1 | ~4 ms / ~50 ticks | 0 | Earlier Fabrizio/MRMC advice reported as a comms-lag compensation |
| Bolt X (Yaskawa) | 4 or 6 | As required | ~3 | Position Delay is now the correct setting |
| Bolt Jr+ (Mitsubishi) | 4 or 6 | As required | As required | Same principle as Bolt X |
| Cinebot (UR / Ethernet) | 4 or 6 | As required | As required | No EtherCAT lag |
Root Cause¶
EtherCAT robots (standard Bolt) communicate on a different timing domain than Ethernet accessories (lens motors, focus devices). Without compensation, focus or zoom can arrive either early or late relative to the physical camera move.
Community history contains two useful Bolt timing references:
- An earlier field note described the EtherCAT/Ethernet lag as approximately 4 ms / 50 ticks.
- A later official relation for MRMC Focus/Zoom motors on Bolt was quoted as Network Buffer 1 / Position Delay 0 / Robot Delay 0.7.
Treat the 0.7 relation as the current practical preset for Bolt + MRMC lens motors, then test on the actual move.
For Bolt X (Yaskawa Motoman controller), there is an additional processing delay in the robot controller itself that must be matched on the focus side.
Resolution¶
Where To Enter These Values¶
| Value | Flair location |
|---|---|
| Network Buffer / NWD Buffer | Setups -> Network Setup |
| Robot Delay | Setups -> Miscellaneous Setup |
| Position Delay | Setups -> Miscellaneous Setup |
Bolt (EtherCAT / Staubli)¶
For MRMC Focus/Zoom motors on Bolt, use the official relation quoted in the chat:
| Setting | Value |
|---|---|
| Network Buffer / NWD Buffer | 1 |
| Position Delay | 0 |
| Robot Delay | 0.7 |
This was reported as the recommended relationship for Bolt robots when focus or zoom lags during fast track-in / track-out moves, especially in macro/target-tracking work.
If working on an older setup or reading older notes, you may also see the Robot Delay described as approximately 50 ticks / ~4 ms. Verify the units and current Flair version before copying values between systems.
Bolt X / Bolt Jr+ (Ethernet-based robots)¶
In Setups -> Network Setup, set NWD buffer to 4 or 6 (confirm by testing).
In Setups -> Miscellaneous Setup, set Position Delay to approximately 3 ticks. This was previously handled by the NWD buffer but the approved setting has moved to Position Delay.
Robot Delay can affect track zero
Simon Wakley: "Changing the robot delay could affect the track zero, so watch for that. If you set it to 15 for virtual wall and zero it, it might change the zero." — verify zeroing after changing Robot Delay.
Test method for focus sync
Simon Wakley's recommended test: set up an end-mount lens with focus gear aligned with the roll centre. Make equal and opposite moves. Put a stick on the focus gear — it should stay in the same place when running slow and fast. If it moves, the timing is not calibrated. Contact Fabrizio for confirmation.
WhatsApp Excerpts¶
"NWD buffer value of 1 for EtherCAT Bolt. For Bolt X / Jr+ use 4 or 6." — Community member (multiple threads)
"There is an approved setting for the BoltX that delays the focus to match the processing delay in the motoman controller. It USED TO be put in the network buffer but now it should be in the position delay and the value is about 3. Fabrizio knows it." — Simon Wakley (2025-05-12)
"Increase Position Delay if Focus is ahead. Increase Robot Delay if Focus runs behind." — Timothy Heys Cerchio (2025-05-11)
"Robot Delay setting corrects comms lag between EtherCAT (robot) and Ethernet (accessories). ~4ms / 50-tick offset — from Fabrizio at MRMC." — Community (multiple)
"MRMC suggested setting for Bolt robots Position Delay = 0 and Robot Delay = 0.7 ... focus always drifting when running these moves even though it checked out when browsing slowly." — Tom D (2024-10-13)
"Ideal official Delay 'relations' for work with MRMC Focus/Zoom motors on Bolt: Network Buffer 1, Position Delay 0, Robot Delay 0.7." — Timothy Heys Cerchio (2025-10-11)
See Also¶
- NET intime not starting — InTime startup failures can also produce focus/robot sync issues
- LENS focus calibration lookup table — lens calibration still needs to be correct before timing offsets are meaningful
- TT focus infinity cartesian drift — target-tracking focus issues that are not pure delay problems