FRICK
QUANTUM™LX AcuAir
CONTROL PANEL 090.510-M (OCT 10)
MAINTENANCE Page 13
DIGITAL BOARD
The information that follows in this section can help locate
problems that can occur with Digital Input and Output
circuit boards, and their interaction with the Quantum™ 4
controller.
Digital Board Description
The Digital Board is actually a small microprocessor
board and programmed to control discrete outputs, or
accept discrete inputs, from external electrical
devices. Each Digital Board has the capability of 24
independent channels or I/O (Input/Output). With the
Quantum™ LX AcuAir Control, some of these I/O
channels are dedicated as to their function, through
the operating system (software), enabled options and
external wiring. Each channel that is used by the
software will have a module plugged into it. A yellow
module indicates that it is used for Inputs, a black
module is used for Outputs. The standard Quantum™
LX AcuAir Control can have up to two Digital Boards
(depending on options).
Communications LED's
The controller is in constant communication with all
Digital (and Analog) Boards. You will notice on each
Digital and Analog board, that there are a pair of
LED's labeled as RX and TX. These letters represent
Receive (RX) and Transmit (TX). These LED's should
be flashing at a high rate during normal operation.
This indicates that the Quantum™ 4, and the Digital
Board that you are looking at, are properly
communicating with each other.
Reference the
JUMPER AND DIPSWITCH
SETTINGS
section later in this manual. This
section contains the dipswitch settings for
addressing the Digital I/O Boards. When
these switches are properly set, the
Quantum™ 4 is able to serially communicate
with each I/O board and provide control
signals and data exchange. If these switches
are not properly set, the result will be lost or
failed communications, or the wrong outputs
being energized, or the wrong inputs being
received.
Connections to the Quantum™
The Frick AcuAir control system utilizes up to two
Digital, and one Analog Boards. To connect all of
these boards together so that the Quantum™ 4 can
control them, they must be interconnected with a
wiring harness that provides all of the necessary D.C.
voltage requirements, as well as the communications
capabilities. A diagram of this wiring harness can be
found later in this manual (see the Power I/O Wiring
Harness drawing). The harness has an 18-pin
connector at one end that plugs into the Quantum™.
Another connector plugs into the power supply. The
remaining three connectors (16-pin) will plug into
each of the Digital and Analog Boards in the system
(up to three total).
Upon close examination of this harness, you will
notice that each of the connectors for both the
Quantum™ and the three possible I/O boards, have
two rows of connections. The wires that are inserted
into the positions of one row, are internally daisy-
chained on each I/O board, to continue the voltages
and signals to the adjacent row. Therefore, any time
that a connector is unplugged from the daisy-chain,
these voltages and signals cannot continue through
the daisy-chain to the next board. Whenever a plug is
not to be inserted into a board, either for service or if
not all boards are present, then a shunting plug (refer
to Recommended Spare Parts list) must be installed
onto the open connector.
The four wires that feed from the power supply to the
Quantum™ 4 provide all of the necessary D.C.
voltage that is required (+5 Vdc, -12 Vdc, +12 Vdc,
and Return or Common). The voltages are passed
through the connector on the Quantum™ 4, and two
new signals are generated by the Quantum™ 4 to be
passed on through the daisy-chain to the I/O boards.
These two signals are the RX (receive) and TX
(transmit). These signals are the means by which the
Quantum™ communicates to the I/O.
The Digital Boards only require the +5 Vdc voltage
and the Return (or common) for logic power. The
communications signals (RX & TX) are required by all
boards.
Logic Voltage (Power) LED
Located on the Digital Board is a
Power
LED. This
LED will be illuminated as long as the
Control Power
switch is ON, and the proper voltage is present at the
Quantum™ power supply. The power supply
generates the +5 VDC voltage, and passes it on
through the Power-I/O harness. This LED does not
indicate however that the proper voltage is
necessarily present at the board, only that the voltage
is enough to energize the voltage sensing circuitry. If
a voltage related problem is suspected with regard to
a Digital Board, the only way to actually determine
this is to read the voltage on a Digital Voltage Meter
(DVM ). This may be accomplished by locating the
white power/communications connector on the board.
Notice that the Digital Board has one of these
connectors on both ends of the board. The associated
power/communications harness will only be plugged
into one of these connectors. Take the red (positive)
probe of the DVM and carefully insert the end into the
"+5V" lead, and the black (negative) probe end into
the "RET" (Return or Common) lead, as shown below:
+5V
RET
