ACC501
Rev. 1.10.0031
©2016, Ambient Recording GmbH
14
6.7 TUNE menu
This menu is used to tune (calibrate) other Lockit devices or for the Controller to calibrate its reference
oscillator to an external source.
The internal reference can be tuned to + - 10ppm with a resolution of 0.15 ppm per digit. The tuning
number DAC is shown on the display as well as recent tuning history. The tuning process may have to
be carried out several times if the tuning error is large (over 4ppm). The tune values are estimated and
the final value approached and met after up to 5 tune processes.
Please note: Always make sure that the timecode output is turned off when tuning
intern or extern to avoid re-jamming a ACL202CT (up to firmware 8.2 it will rejam every
5 seconds and thus cause false readings when the oscillator is not tuned in yet) or
crosstalk from the timecode signal. If timecode out is “on”, you will get a warning
message to turn it off first.
Press 1, Tune extern:
The device connected can be tuned to the Controller.
Please make sure “tune signal out” is off, i.e. no wave symbol displayed next to “INT”
(see command # 3).
Press 1, Ref:
The tuning reference signal of the external device is scanned and compared to the
internal clock. This is the most used mode as the controller is master in most cases.
After scanning, the DAC value of the external device is read out and a new DAC or “tune value”
proposed. You will be asked to "confirm or edit new tune value". To confirm, press "Enter". To change
values, use the "Up" or "Down" Keys.
Repeat tuning until difference is not more than 0.1 ppm.
Press 2, Man:
The tune steps can be entered manually. (1 DAC value difference equals 0.15ppm)
Press 2, Tune intern:
This function allows calibrating the controller’s internal reference oscillator to an
external source.
