User's Manual

Page 22 of 44

Frequency tuning (FT)

FT (Frequency Tuning):

FT is designed to minimise problems with interfering RF frequencies by moving the frequency of the receiver

to a more optimal placement relative to the interfering frequency. FT cannot alleviate problems if the

interfering RF transmitter is sending on the same frequency as the handsets.

The FT has three frequencies it tries out: The centre frequency found during the PCB-test, a frequency a bit

lower and one a bit higher. The two last frequencies are found by empiric testing of a number of units trying

to ﬁnd the optimum frequency that gives least interference but still adequate reception. It takes approx. 7

seconds to complete the FT.

How to activate the FT:

The FT can be activated at any position of the TWINDRIVE

TD.

1. Check Software and Hardware version according to above speciﬁcation

2. Check that FT is enabled in the conﬁgurator, always enabled with standard conﬁguration of TD3.

3. Be sure that the TD is connected to the mains

4. The HB has to be paired to the TD

5. Test and check that the TD can run when the HB is close to the TD (0-30 cm). Only to be sure that the TD

and the HB is paired.

6. The optimum frequency is achieved when the handset can just barely activate the TD.

7. Activate FT by pressing two buttons on the HB at the same time: backrest up and backrest down. These

buttons must be pressed during the entire operation for the FT to be successful. Keep the keys pressed, the

frequency is now stored in the unit, otherwise the FT returns to the last stored frequency. Keys have to be

pressed for at least 7 seconds. It does not matter that the keys are pressed for a longer time.

Return to factory setting

Push shortly on the reset button. Do not push on the HB button.

Please observe:

• Should the FT see another key-press from the same handset (e.g. the user has released one of the two

buttons) the FT immediately terminates and the system returns to normal operation on the old selected

frequency.

• Should the FT lose connection to the HB it will still continue scanning as the reason could be because the

currently scanned frequency is simply too bad for reception.

• The FT can be restarted again at any time by the user and can be disabled completely by conﬁguration of the

TD3.

• If the FT is disabled and a manual frequency has been entered, the system cannot be returned to centre-

frequency by pressing the reset button.

• If the FT somehow has selected an even worse frequency than centre-frequency (e.g. because the interfering

frequency has moved) and the FT can no longer be activated (because the unit cannot see any RF), the FT

can be returned to centre-frequency by following the procedure for pairing handsets. It is not necessary to

actually re-pair the handsets, simply press the reset button shortly while ready for re-pairing is enough.

HB12RF

HB22RF