Jastram ENGINEERING DSC 100 - Digital FFU Command Device

MCP - Inputs
Page 36 of 80
Specifications
Potentiometer Supply:.................. 5 VDC
Potentiometer Range:.................. 1kΩ to 5kΩ
Cable Break Protection ................ Yes
Connector ....................................3.81mm pitch pluggable screw terminals
Installation
Commissioning
Each analog FFU command device must be calibrated through the SCP
Command Calibration window of the DSC Setup Software (see section
4.1.2
) or through the Calibration menu of the keypad setup (see section
4.2.5
). The calibration procedure informs the system of the input device’s
midship, port maximum and starboard maximum positions. The polarity of
each FFU command input device can also be reversed in the SCP
Configuration window of the DSC Setup Software (see section 4.1.1
) or
through the SCP menu of the keypad setup (see section 4.2.2
).
2.3.5 Digital FFU Command Device
Description
The FFU Digital Input is connected to a steering control device such as a
Digital Helm that uses an incremental optical encoder. The incremental
optical encoder outputs a 2-bit quadrature signal capable of expressing
magnitude and direction. An optical encoder, unlike a potentiometer, uses
no wearing parts to produce its signals and therefore has an exceptionally
high service life. This connection provides a 5V supply to power the
optical encoder. Since an incremental input device does not have any
built in hard stops, the number of turns of the device which will represent a
hard over to hard over command can be programmed through the DSC.
FFU input devices can provide full control of either on-off or proportional
directional valves.
Upon selecting the digital device as the active mode of steering control,
the system will initialize the current rudder position as the starting rudder
command. The MCP then reads the 2-bit input pulses from the encoder
and determines how much the input device has been turned and in which
direction. This information is used to alter the rudder position command
signal. An ROI signal is available to display the present rudder command
of this input.
Doc No.: MAN01504, 20-02-06 DSC 100 & MCP 100 Manual