The instrument adopts the coil spring take-up device with double constant force. The tension of the wire rope is greater than 55N. It is suitable for the measuring range 0~15m. (The measuring range can reach 20m adopting the special manufacturing.) There is a precise gear lead screw driving device in the interior of the instrument on which four travel switches can be installed at the utmost. The four travel switches correspond respectively with four controlling points within the measuring range. Stepless adjustment can be carried on through respective position at the message transmission position of the each switch. The product is suitable for opening measuring and control of the plain batten gate, arc-like gate, leaf gate, fast gate and the different valves.

The product has the following characteristics:
The slipping phenomenon of the measuring wire rope is eliminated in virtue of the winding drum
     device of the constant tensional takeup. The counter weight is not required when using. There is no
     limit for installation space.
Automatic rope-winding mechanism is provided to achieve the automatic rope-winding function.
Passive contact switch is provided in the interior to achieve the gate position control.
The single direction stopping mechanism (in the stopping position, the wire rope is only for out ) is
     provided for easy assembly on the spot.
The rope–broken stopping function is provided. Protection function starts as soon as the rope-broken
     failure occurs.
The product has high measuring accuracy, easy operation and maintenance. Long term, continuous,
     stable and reliable operation can be provided.

The opening measuring and control digital display unit can provide several output types for selection.

1 Measuring function
Measuring range: 0 ~ 6m, 10m, 15m, 20m(special)
Resolution: 1mm
Measuring accuracy: ± 3mm
Remote transmission distance of the output signal: ≮ 500m

2 Limit switch (Omeron Company)
The four travel switches (or electro-optical switches)can be installed on the opening measuring sensor device through the precise gear lead screw driving device. The four travel switches correspond respectively with four controlling points. Stepless adjustment can be carried on through respective positional screw at the message transmission position of the each switch. The repetition accuracy of the switch: ≤± 3mm

3 Sensors (adopt all good quality imported products)
Incremental electro-optical encoder: increment pulse signal for the output: phase A, phase B, phase Z
Multi-ring absolute electro-optical encoder: SSI (recommendation) for the output, PROFIBUS or CAN
     interface

4. Protection level IP 65

5 Operational conditions:
Power supply DC 24V ± 10%
Environment temperature: － 20 ° C ~ ＋ 55 ° C
Environment humidity: 35% ~ 95% RH

There are two kinds of rope-out methods for FDK-IV gate opening instruments. It adopts downward (vertical) rope-out method for corresponding vertical cylinder (The plain batten gate and the opening instrument is installed on the arc-like door of the oil cylinder.). It adopts forward (horizontal) rope-out method for corresponding horizontal cylinder. (The plain batten gate and the opening instrument is installed on the arc-like door of the oil cylinder.).The method can always guarantee in the horizontal state of the opening instrument after installation.