Woodward 2301E, Инструкция по установке и эксплуатации, Страница: 24 / 182

2301E Digital Control Manual 26641
14 Woodward
The 18
–36 Vdc input power must be supplied from a power
supply/battery charger certified to IEC standard with SELV (Safety
Extra Low Voltage) classified output. The installer should properly
size wiring and fusing for the input power and PT/CT circuits.
Discrete Inputs (Terminals 34
–41)
Discrete inputs are the switch or contact input commands to the 2301E control.
They interact in such a way as to allow engine control and power management
under a variety of conditions. The user has the capability to change the logic of
the discrete inputs through the software interface. For example the user can now
change the logic of the Run / Stop discrete input from Close to Run and Open to
Stop to Close to Stop and Open to Run. All of the discrete inputs have this
capability. (Note: double pole configuration below for critical I/O going between
points physically > 30 m in length apart.)
The following example is using the default logic for the discrete inputs. Positive
Voltage is supplied to the discrete input terminal when an input switch or relay
contact closes. This will cause the input state for that dis
crete input to be “TRUE”
(displayed as “CLOSED”). The input terminal will be open circuited when the
input switch or relay contact opens. This will cause the input state for that
discrete input to be “FALSE” (displayed as “OPEN”). When the input switch or
relay contact is closed, the voltage supplying the discrete inputs should be
present from the appropriate discrete input (terminal 34, 35, 36, 37, 38, 39, 40, or
41) to terminal 33 (common). Terminal 33 is the common return path for all of the
discrete input channels. A lower voltage indicates that the switch contacts have
too high a resistance when closed and should be replaced. These terminals must
be isolated from ground.
In systems that provide an external low voltage source to power the 2301E
control, the discrete inputs may be powered by this external low voltage. The
voltage source used must be capable of supplying 100 mA at a voltage level of
18 to 36 Vdc. Connect the external low voltage source negative to terminal 33(
–).
Connect the external low voltage source positive to the appropriate input switch
or relay contact and connect the mated switch or relay contact to the
corresponding discrete input terminal on the 2301E control.
In systems where the external low voltage dc power is not appropriate, the
discrete inputs may be powered by the internal 24 Vdc Discrete Input Power
source at terminal 31 and 32. This source is capable of supplying 100 mA at a
voltage level of 24 Vdc. Connect the internal 24 Vdc voltage source positive from
terminal 31 to the appropriate input switch or relay contact, and connect the
mated switch or relay contact to the corresponding discrete input terminal on the
2301E control. Assure that a connection exists between terminal 32 and terminal
33 when using the internal Discrete Input Power. Do not power other devices
with the internal discrete input power source, and assure that the switch or relay
contacts used are isolated from any other circuit or system. The internally
provided contact wetting voltage may not be used for anything other than DI
Contact wetting; it is dedicated to this function.
Discrete inputs with cable lengths where the end points are
physically greater than 30 meters apart and which are used for
critical functions, such as emergency stop, should not be floated in
either an on or off state. These inputs should be switched to either
+24 Vdc or ground, never floated or tied to reference with a resistor.