Featured Products - MFS -

Split-Range Transmitter — MFS

This device is to generate two current signals from a single controller’s current output source for the purpose of split ranging control.


Plug-in type construction
	Main advantage is ease of installation and troubleshooting.
Two combination types of current output signals
	Parallel and V-shape (inverse direction) characteristics can be chosen.
Control output monitor terminals
	Outputs can be easily checked at any time via front panel jacks without disturbing output connections.
Minimizes DCS outputs to control final control elements
	Expensive DCS output points can be reduced by 1/2.

Figure 1. Operation of V-shape characteristics Split-Range Transmitter, Model MFS-V.

Figure 2. Adjustable range of V-shape characteristics Split-Range Transmitter, Model MFS-V.

Figure 3. Operation of parallel characteristics Split-Range Transmitter, Model MFS-P.

Figure 4. Adjustable range of parallel characteristics Split-Range Transmitter, Model MFS-P.

The Model MFS Split-Range Transmitter is a signal conditioner that can be used to manipulate two control valves with only one input signal. This type of function is usually obtained by using a valve positioner’s split ranging action. However, by using the Model MFS, ordinary control valves that are configured for a 4 – 20 mA input can be used for this purpose. As for the characteristics combination of two control output signals, V-shape (inverse) and parallel types are offered. Either one can be used depending on the valve’s operating direction. With a DCS, the number of control outputs can be reduced from two to one if the Model MFS is used.

The V-shape characteristics model (Model MFS-V) is typically used when temperature is controlled by using hot and cold water, and either line valve has the same opening direction in relation to the input signal. As an example, a cold water line valve is controlled from fully open to closed with the input signal range of 4 – 12 mA DC while the hot water line valve is controlled from closed to fully open with the input signal range of 12 – 20 mA DC (See Figure 1).

With the Model MFS-V, 0% (4 mA) on output signal No.2 can be adjusted over the input range of 10 – 20 mA DC. In the same manner, 0% (4 mA) on output signal No.1 can be adjusted over the input range of 4 – 14 mA DC. That is to say, the Model MFS provides the flexibility to adjust both outputs so that there is some overlap between them (See Figure 2).

The parallel characteristics model (Model MFS-P) is typically used when temperature is controlled by using hot and cold water where these line valves have different opening directions in relation to their respective input signals. For example, a cold water line valve is controlled from fully open to closed with the input signal range of 4 – 12 mA DC while the hot water line valve is controlled from closed to fully open with the input signal range of 12 – 20 mA DC (See Figure 3).

With the Model MFS-P, 100% (20 mA) on output signal No.2 can be adjusted over the input range of 10 – 20 mA DC. In the same manner, 0% (4 mA) on output signal No.1 can be adjusted over the input range of 4 – 14 mA DC. This shows that the Model MFS provides the flexibility to adjust both outputs so that there is some overlap between them (See Figure 4).