SRC8 - Switch &
Route Controller Application Information
General
Information:
The SRC8 can be used in a number of applications. Track
plan panels, Centralized Traffic Control (CTC) panels,
fascia boards, motor drive and switch position reporting
(feedback) are some types of uses for the SRC8.
The power supply connector is non polarized. Either
terminal can be connected to plus or minus of the power
supply. When multiple SRC8s are used they can be all
connected to one power supply. The power supply must be
able to supply the current for all the SRC8s. The
plus and minus of the power supply must be connected to
the same power input terminal on each SRC8.
Note: When two or
more SRC8s are powered from the same power supply there
can be a fault ground condition if one of the power wires
to one of the SRC8s is loose. That SRC8 will still be
getting power because loconet ground provides a power
path to the SRC8 with the loose power wire. When this
condition occurs, that SRC8 loads down loconet.
Be sure the power supply you use puts out the correct
filtered DC voltage when connected to the SRC8. Most
analog 'Power Packs' will not work because they do not
provide smooth (filtered) DC power. Also it must be
isolated from the system ground. That is, the power
supply can not have one of it's outputs connected to
ground (booster ground, loconet ground, house wiring
ground, etc). Some wall transformers have a ground
connection. Three prongs into the wall suggests the
negative output of the power supply is grounded. Only
SRC8s should be powered from this power supply.
The minimum LED current limiting resistor value is 470
ohms. This is a general guide line for a typical LED.
Resistor values of 1K work well with many LEDs. The
higher the resistance value, the lower the power supply
requirements.
In the examples below only switch group 1 is shown being
used. However, any group could be used and not all the
groups have to be configured the same.
Known Problems:
10/21/02
Using alternate addresses. Activating an input sends the
wrong alternate address. When an input in group 2 through
8 is activated, it actually sends it's alternate address
plus it's group number minus one. The LEDs respond
correctly to received messages with an alternate address.
If you are not using alternate address, this problem does
not effect SRC8 operation.
SRC8s with this problem can be identified by a single
silver mark on the integrated circuit (IC) closest to the
LocoNet connectors.
8/9/04
When CV 2, option 6 is enabled, group 1 inputs do not
work. If you are not using option 6, this problem does
not effect SRC8 operation.
SRC8s with this problem can be identified by four silver
marks on the integrated circuit (IC) closest to the
LocoNet connectors.
11/21/05
Using alternate addresses. If an alternate group address
has been defined, the SRC8 will respond to a sensor type
message in addition to the switch command message with
the same address. To avoid this problem do not define an
alternate address the same as a sensor address.
This problem has been corrected in version 4.3 of SRC8s
(marked 43).
5/22/08
Executing routes. The second cell in a route does not
operate correctly when inputs are configured for feedback
reporting. SRC8s with this problem can be identified by
50 marked on the integrated circuit (IC) closest to the
LocoNet connectors.
Arrange for problem solution by contacting us .
LED connections:
Figure 1 below shows three different configurations in
which LEDs and the associated resistors could be
connected to a SRC8 group output. In normal operation
where only one of the group LEDs is turned on at a time,
all three configuration work OK. However, during lamp
check at power on and in "Smart Programming" mode when
both LEDs are turned on, both LEDs in configuration
Figure 1B may not be on and both LEDs in Figure 1C will
be off.
Note that the LED configuration in Figure 1A can also
represent a three legged bi-color LED (common cathode).
While the configuration in 1C can represent two legged
bi-color LEDs. Figure 1D can represent a three legged
bi-color LED (common anode).
Track Plan Panel:
Figure 2 below shows how push buttons and LEDs can be
connected to the SRC8 inputs and outputs. In this case,
when a button is pressed, the LEDs show the state of the
switch on a representation of the track plan. The push
buttons could be located near the LEDs or some distance
away on another panel.
The buttons could also be placed on a fascia board
without the use of the LEDs to provide local control of a
switch or a route.
CTC Panel:
Figure 3 below shows a CTC panel with a US&S
configuration. The switch lever can be moved freely at
any time. However, nothing happens until the button
(sometimes called "code start button") is pressed. Once
the button is pressed, the LEDs indicate the state of the
switch.
Switch Machine Drive:
Figure 4 below shows how a low current stall type switch
machine can be connected to the SRC8 outputs. The SRC8
has been tested with the Tortoise™ switch
machine and can drive up to eight of them. Programming is
the same whether using a switch machine or LEDs.
The SRC8 is NOT compatible with the SwitchMaster motor.
Each switch machine is connected to one of the SRC8 group
outputs. One of the motor terminals is connected to the
closed (green LED) output and the other motor terminal is
connected to the thrown (red LED) output. When the SRC8
receives a switch command for that group, lets say a
close command, 5 volts is applied to the closed output.
The thrown output is at ground, so 5 volts is applied to
the motor. It then moves in the close direction.
Likewise, when a throw command is received for that
group, 5 volts is applied to the thrown output. The
closed output is now at ground, so 5 volts is applied to
the motor in the opposite direction. Consequently, it
moves in the throw direction.
Since the SRC8 uses 5 volts for motor drive, the switch
machine moves slower than if 12 volts were applied.
The inputs can be used to control the switch machine or
can be configured as feedback as discussed next.
LEDs can be uesd as switch position indicators. The SRC8
does not have enough voltage output to drive
a Tortoise™ in series with an LED. However,
you can drive a Tortoise™ in parallel with a
LED resistor combination (in this case the resistor
should be at least 1000 ohms). You can also use the
internal contacts of the Tortoise with a LED resistor
combination powered by 5 volts from the SRC8 or by track
voltage.
Switch Position Reporting:
The SRC8 can be used to report switch position which is
sometimes called switch position feedback. In some
situations it is desirable to know for sure that a switch
actually moved when it was commanded. Figure 4 below
shows the SRC8 inputs connected to
the Tortoise™ switch machine internal
contacts. Figure 5 below depicts micro
switches mechanically linked to the switch and connected
to the SRC8 inputs. When the switch moves internal
contacts close or a micro switch is activated, grounding
a SRC8 input. The SRC8 then sends a LocoNet feedback
message.
Figure 6 below shows how the SRC8 inputs can be connected
to a solenoid type switch machine. When the solenoid is
energized the pulse is applied to one of the SRC8 inputs
through a diode. The SRC8 then sends a LocoNet feedback
message.
10 Pin Connectors:
Figure 7 below shows the SRC8's connector pin out and
group number relationship. The view is from the top of
the connectors. Both input and output connectors have the
same pin out. The Team Digital TSA board plugs directly
into these connectors can be used for easy screw terminal
connections. Also flat ribbon cable insulation
displacement (IDC) type mating connectors can be used.
Mating connectors and ribbon cable are available at some
Team Digital Dealers and at.
Jameco : http://www.jameco.com
mating connector part # - 138377
10' flat ribbon cable, gray part # - 643794
10' flat ribbon cable, multicolor part # - 639672
connector installation tool part# - 73252
