Manual OC32/NG
VPEB
Control your Miniature World
Page 8 of 48
Version 1.0 – December 15
th
, 2017
2017 Leon van Perlo
Fig 2: U485
1.3
OC32 I/O Pins
The OC32 I/O Pins are used to connect the devices in your miniature world. The OC32
I/O Pins need to be equipped with ‘drivers’ that fit the electrical characteristics of the type
of device which is connected, such as:
•
Incandescent lamps
•
LEDs, common anode (plus) or common cathode (minus)
•
Relays
•
DC motors, also bidirectional (electronic reverse)
•
Servomotors
•
Memory wire
•
Solenoids for e.g. turnouts and decouplers (up to 4.8A peak-current)
•
Pushbutton, switch or other contact
When you buy the OC32, standard drivers are installed, but you may need to change the
drivers, depending on your specific application. Changing drivers can easily be done by you as
a user.
We will cover the drivers in much more detail later in this manual
1.4
Communication
The standard version of the OC32/NG is equipped with 2 serial interfaces: An RS485
interface and an RS232 interface. Via these interfaces the OC32 can be configured and
controlled. It can be connected to a PC, a Dinamo or Dinamo/MCC system. A singe
connection supports up to 96 OC32 modules. Both serial interfaces can be used
simultaneously.
The RS232 interface is unidirectional. This means you cannot use this interface to read data
from the OC32, nor can you verify the OC32 configuration through this interface. The
RS232 interface is mainly there for compatibility with the OM32 and for situations where
you want to control OC32’s with a standard PC COM-port.
The RS485 interface is bidirectional. It offers full
control capabilities. Using RS485 you can bridge a
distance up to 1.200 meters!
RS485 is not what you find on a standard PC.
Therefore VPEB designed the U485. This extremely
compact module simply turns any USB port into an
RS485 interface.
1.5
DCC
The OC32 can be ordered with a DCC input
1
, by which the module can be controlled from any
DCC compatible digital system. The OC32 can then function as a very flexible Basic DCC
Accessory Decoder and as an Extended DCC Accessory Decoder. Unfortunately there are
few DCC command stations today that transmit Extended ADCC Accessory Packets. The
amount of basic and extended DCC addresses and the basic and extended DCC start
addresses used can be configured by software.
The OC32 cannot be configured through DCC. The possibilities are extremely large and
configuring through DCC would become very complex to the user. So configuration needs to
be done through one of the serial interfaces.
1
The DCC Interface can also be added afterwards by the user. All components needed are ‘through hole’ (so not
SMD). You need to solder to the PCB however.
Control your Miniature World
VPEB
Manual OC32/NG
2017 Leon van Perlo
Version 1.0 – December 15
th
, 2017
Page 41 of 48
6.4.10
Motors (unidirectional)
OC32 I/O Pin: 500mA Sink Driver
or
OC32 I/O Pin: OC32-ADM/SI 4,8A Sink Driver
Driving a DC motor, which needs to run in one direction
only, is quite simple. Connect the motor between Vp and
the output like in Fig 36.
When the motor draws more current than 350mA at maximum load (not being maximum
speed) preferably use the OC32-ADM/SI.
6.4.11
Motors (bidirectionall)
OC32 I/O Pin: Sink Source Driver
or
OC32 I/O Pin: OC32-ADM/FH 4,8A H-bridge
A bidirectional motor is a motor that runs into two directions. An example is a turnout
motor which moves slowly. The problem is reversing the current to have the motor run the
other way around. This can be done with a so called "H-bridge" circuit. By putting both a Sink
Driver and a Source Driver into the OC32 such a H-
bridge is established. The motor has to be connected
between two consecutive outputs.
The motor runs in one direction when output Q(x) is
active. When output Q(x+1) is active the motor runs
in the other direction. Also the speed can be adjusted.
Take care: It is of vital importance that Q(x) and
Q(x+1) are never active at the same time.
This can be set-up in the OC32 configuration.
When the motor draws more current than 350mA at
maximum load (not being maximum speed) preferably use the OC32-ADM/FH
6.4.12
Servo Motors
OC32 I/O Pin: Resistor array
A servo motor is a motor with integrated electronics, that can be moved into a desired
position by means of a digital control signal. The servo motor requires a separate power
supply to operate. The voltage usually has to be between 4,5V and 6V. Details can be found
in the documentation of the manufacturer.
Normally speaking a servo motor has three
leads: GND, Power and input. These have to
be connected according to figure 38.
Take care: A servo motor can draw quite
some current and especially the cheaper
versions generate a lot of interference. To
prevent negative impact on the
Electronics, it is wise to incorporate a
separate stabilizer and capacitor into the
5V power supply of the servo motor.
Fig 36: Conneting a motor
Vp
Q(x)
M
Vp
Q(x)
M
M
Fig 37: Connecting bidirectional motors
Q(x+0)
M
Q(x+1)
Q(x+2)
Q(x+3)
Q(x+4)
Q(x+5)
Q(x+6)
Q(x+7)
M
M
M
Q(x+0)
M
M
Q(x+1)
Q(x+2)
Q(x+3)
Q(x+4)
Q(x+5)
Q(x+6)
Q(x+7)
M
M
M
M
M
M
Fig 38: Connecting a servomotor
GND
Q(x)
Input
5V
+
-
GND
Q(x)
Input
5V
+
-
