Woodward 723PLUS Technical Manual page 38

723PLUS Digital Marine Control
When the maneuvering mode input is closed, the engine speed reference will
ramp from its current value to the maneuvering speed setpoint at the 05 RAISE
SPEED RATE. This is true even if the engine speed is actually higher than the
maneuvering speed setpoint when the maneuvering speed input is closed.
When in remote operation, the control ramps the master or unclutched engine
speed to the reference value set by the Remote Speed Setting input as
configured, based on the raise or lower rate.
The Remote Speed Setting operates from 4 to 20 mA (1 to 5 Vdc). The values of
the remote reference set points must be set between the raise and lower limit set
points. The 4 mA (1 Vdc) Remote Speed Setting may be set to a lower or higher
speed than the 20 mA (5 Vdc) set point, providing for either direct or reverse-
acting remote speed setting. Remote input speed settings are found in service
mode, under the header G**SPEED REFERENCE**, at prompts 08 REMOTE
REF AT 1 V and 09 REMOTE REF AT 5 V.
Between 4 and 20 mA (1 and 5 Vdc), the control determines the required speed
reference based on a straight line between the 4 mA and 20 mA (1 and 5 Vdc)
Remote Speed Reference set points (see Figure 3-2). If a difference is detected
between the present speed reference and the remote speed reference, the
present speed reference is ramped up or down at the raise or lower rate until the
present speed reference matches the remote speed reference rpm value. The
remote reference will not increase/decrease the speed reference above the raise
limit or below the lower limit.
Below 2 mA (0.5 Vdc) or above 22 mA (5.5 Vdc), the Remote Speed Setting
input is considered failed or out of range. While the remote speed input is failed
or out of range, the master engine speed can be raised or lowered with the
raise/lower speed contact inputs. Remote speed input failure or out of range is
latched, after a configurable delay time, and must be reset to restore normal
operation. Toggling the alarm reset, once the failure is repaired, resets the input
failure latch. The delay time setting is found in configure mode, under the header
E**ALARM/SD CONFIGURE**, at the prompt 01 ALARM DELAY TIME.
A clutch request ramps the slave engine speed to the master speed reference at
the 07 SLV-MST RAMP RATE found in service mode under the header
G**SPEED REFERENCE**. Once the slave engine speed matches the master
engine speed reference, the ramp switches to a very fast rate to force the slave
engine speed to immediately track the master engine speed reference.
A torque sharing bias signal is applied to the speed reference to effect torque sharing
once both engines are clutched in and torque sharing is enabled. The torque sharing
signal biases the speed reference of each engine to distribute the torque equally
between both engines. The torque sharing bias signal is applied after the speed
reference ramp rate limiter. This ensures the torque sharing response is not
restricted by any speed reference ramp rate settings. The torque sensor analog input
and calibration settings are found in service mode, under the header L**ACT /
TORQUE CALIB**, at the prompts TORQUE IN @ NO LOAD and TORQUE IN @
MAX LOAD. Should the torque signal analog input fail, the actuator signal fuel
demand is provided by the 03 SCALED ACT COMMAND and calibration settings
found in service mode, under the header I**ACT / TORQUE CALIB**, at the prompts
01 ACT OUT @ NO LOAD and 02 ACT OUT @ MAX LOAD.
The torque sharing and fuel limiting functions both depend heavily
upon accurate L**ACT / TORQUE CALIB** settings. Carefully
determine and enter the L**ACT / TORQUE CALIB** settings and re-
verify these settings following any related mechanical changes
(linkage, actuator, etc.). Failure to do so may result in unequal torque
sharing and incorrect fuel limiter operation.
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Manual 26482
Woodward