FIELD HAND UNIT
The new Field Hand Unit (FHU), has been designed for use with any of the True Technology SupaSlim or Custom Wheels which have onboard electronics, and takes the place of a PC for portable use. Note that the FHU cannot be connected to a PC either directly, or in-line with the filter wheel. Should you require that capability you should choose a wheel with offboard electronics, where a conventional hand-unit is supplied as standard. The picture above shows a the FHU. There is only one connection, and that is via the RJ 6/4 cable supplied with the onboard version of the filter wheel. The display shows zero, which is the default (non-initialised) state on power on. Note that power is supplied from the filter wheel via the same RJ 6/4 cable.
If the wheel is already powered up and initialised at the time the FHU is plugged
into the RJ cable, the FHU itself will not know either the type of wheel (5,6,7 or
8 way) or the filter position. The wheel on the left is actually a 6 position wheel
with a 5 + dark internal disk (5 x 1.25" filter + dark frame), and is at the 'Home' position, which is the filter No 1 position (always the dark position in the case of 'd' disks). In order for the FHU to initialise, the home/reset button at lower centre of the unit is pressed, and this will re-initialise the wheel as follows:
On pressing the home/reset button a letter H will be shown on the display, and at the same time the wheel will initialise. Note that the internal disk is between filter positions (actually turning) in the picture shown, while it is going through this process. At the end of the initialisation process the wheel returns to the No 1 'Home' position and signals the wheelsize to the FHU:
You will see that a figure 6 is on the display, yet the wheel is at the dark, filter No 1 position. This is only a transient condition. It is to tell the user which size of wheel is installed and will appear on the display for around 1.5 seconds after the wheel has initialised. Thereafter the display will revert to a 1 to show that the filter currently selected is No 1:
We could have arrived at the same state if BOTH the wheel and FHU had been powered on together, ie the RJ cable was already linking the two. A zero would be shown on the display of the FHU until the wheel had initialised, then a 6 for 1.5 seconds followed by a 1, as above.
This shows the internal disk REALLY at position 6, which is down one from the Home position. Note that the UP/DOWN switch can change only one position at a time. However, if you keep the switch continually pushed to either up or down, the wheel will continually turn in that direction, the display being updated as each filter position is passed. The top switch is a bright/dim switch for the LED display. Holding the switch to the right will gradually increase the display brightness, and holding the switch to the left will gradually decrease the display brightness, right down to zero. When the FHU is powered on the display defaults to mid brightness.
Price of the FHU in UK is £ 75 including VAT