# Enabling Autolock, FineLock or Long Range FineLock

Trimble instruments provide Autolock technology for locking onto and tracking remote moving targets.

Some instruments also provide FineLock and Long Range FineLock technology for better performance when measuring to static targets when there are two prisms close together.

Use:

- FineLock to lock onto and measure to a prism 20 m–700 m away.

  If the instrument is fitted with the FineLock lens aperture accessory, you can use FineLock technology to lock onto and measure to a prism less than 20 m away.

- Long Range FineLock to lock onto and measure to a prism 250 m–2500 m away.

The separation between targets should not be less than 13' 45" (4 mrad).

The software warns if the distance to the prism is outside the supported range and prevents the measurement from being taken. However, if the software is unable to measure the distance, for example when measuring angles-only measurements, the software cannot display a warming message and will store the measurement. Measurements taken to prisms outside these ranges when FineLock or Long Range FineLock is enabled are unreliable and should not be used.

FineLock and Long Range FineLock technology always take precedence over TRK, DR, or Autolock modes and cannot be used at the same time. If you enable FineLock or Long Range FineLock technology, then Autolock is automatically disabled. If you enable FineLock or Long Range Finelock when TRK or DR mode is enabled, the observation is measured with STD mode.

To enable Autolock or FineLock

1. Configure the Target lock method and related settings in the Target controls screen.

2. Tap the Instrument icon in the status bar to open the Instrument functions screen.

3. Tap the button for the configured target lock method to enable it. The Autolock, FineLock, or LR FineLock button is yellow when enabled.

A search is automatically performed if a measurement is initiated when Autolock is enabled but the instrument is not locked to the target.

When GPS search is ready, a GPS‑aided search is performed instead of a standard search. To perform a standard search, pause GPS Search, or tap Search in the Joystick screen.

The Long Range FineLock hardware is not coaxial with the telescope. To eliminate the vertical errors associated with non‑coaxial Long Range FineLock hardware, you must observe all observations to points on both face 1 and face 2.