SBC-1 Applications Examples
The Industrologic SBC-1 is capable of a multitude of interface and control applications. Its many input and output signals can be connected to a wide variety of devices and signals.The following examples show how to connect the SBC-1 to other Industrologic products:
- Connecting the digital outputs to a RIO-8-OC (open collector) relay board
- Connecting the digital I/O to a TB-22 breakout board
- Reading switches with the digital inputs
- Counting switch closures with the interrupt inputs
- Reading a potentiometer with the analog input
- Using the analog input to read the temperature
with an LM34 temperature sensor circuit
- Driving an external relay with a digital output
- Driving LED's with the digital outputs
- Connecting the digital inputs and outputs to a Solid State Relay module mounting board
- Powering the SBC-1 with DC through the terminal blocks
- Powering the SBC-1 with AC through the terminal blocks
Connecting the digital outputs to a RIO-8-OC (open collector) relay board
The SBC-1 digital output circuits use "open-collector" NPN transistors that can directly switch relay current to ground, allowing them to be easily connected to relay circuits like those on the Industrologic RIO-8-OC relay board.
The +12 needed to operate the relays must be obtained from an external 12 volt power supply. However, this power supply can also power the SBC-1 from its screw terminal block connections rather than using the wall block transformer supplied with the SBC-1.
(If the relays on the RIO-8 are switching high currents or inductive loads such as motors, it may be best to power the SBC-1 from the wall block transformer and use the 12 volt power supply only to power the relays on the RIO-8.)
The IOSEL jumpers for IO1-IO8 should be set in the lower position.
Connecting the digital I/O to a TB-22 breakout board
IO1 through IO8 are connected to screw terminal block connections on the SBC-1 as well as going to the 50 pin header "RACKIO" connector and can be selected as inputs or outputs with the IOSEL jumpers.
If screw terminal connections are needed for 24 inputs, outputs, or a combination of inputs and outputs, an Industrologic TB-22 breakout Board can be connected to the "RACKIO" connector using the ribbon cable included with the TB-22.
The IOSEL jumpers for IO1-IO24 should be set according to how each individual signal is used, in the upper position for use as an input, and lower position for use as an output.
Reading switches with the digital inputs
Up to 8 switches can be connected to the digital input signals available at I01 through IO8 at the terminal block connectors.
The IOSEL jumpers for IO1 through IO8 must be placed in the upper position to select these IO pins as inputs.
The digital inputs have on-board 10K pull-up resistors to +5 volts so external pull-up resistors are unnecessary. (It can't get much simpler than that, can it?)
Counting switch closures with the interrupt inputs
Switches, relays, or other contact closure devices can be connected to the interrupt input signals at the terminal block connectors to count closures. These inputs have on-board 10K pull-up resistors to +5 volts so external pull-up resistors are unnecessary.
Reading potentiometers with the analog inputs
Voltage sources from 0 to +5 volts can be connected to the analog input signal AI at the terminal block connector. Potentiometers can be easily read by using the +5 available on the SBC-1 to "power" the pots, but the current used should be less than 100 milliamperes. Using pots that are 1000 ohms or greater is recommended.
Using the analog input to read the temperature with an LM34 temperature sensor circuit
The analog input can be used to read an LM34 precision temperature sensor, either directly, or using a circuit to scale the output. An LM34 produces .01 volt per degree fahrenheit, therefore the 8 bit A/D on the SBC-1 will give one count for every .0195312 volt. Check the LM34 data sheet for connections and detailed information.
By using an op amp to amplify the signal by 1.95312, each bit of the A/D converter will represent one degree, and the temperature can be obtained by simply reading the analog input VIN1, with no calculations necessary.
Determining the temperature by reading the LM34 directly requires a program with the following calculations.
10 V=VIN1 20 A=V*90/100 30 I=(V*90 MOD 100) 40 B=V*6/100 50 J=(V*6 MOD 100) 60 T=V+A+B 70 K=I+J 80 IF K<50 GOTO 120 90 T=T+1 100 IF K<150 GOTO 120 110 T=T+1 120 PRINT T 130 GOTO 10
Driving an external relay with a digital output
An external relay can be activated with one of the digital output signals available at IO1 through IO8 at the terminal block connectors.
The IOSEL jumper for that particular IO signal must be placed in the lower position to select this IO pin as an output.
The digital outputs have open collector transistors that can switch the relay current to ground, and current to operate the relay can be obtained from the +5 available at the terminal block connector. The current used for this purpose should be less than 100 milliamperes total for all relays or other devices operated in this manner. If the relays require more current than this, a separate power supply should be used.
Driving LED's with the digital outputs
Light emitting diodes can be activated with the digital output signals available at IO1 through IO8 at the terminal block connectors.
The IOSEL jumpers for IO1 through IO8 must be placed in the lower position to select these IO pins as outputs.
The digital outputs have open collector transistors that can switch the LED current to ground, and current to operate the LED's can be obtained from the +5 available at the terminal block connector. (The LED's must have series resistors to limit the current to that specified for the particular LED.)
Connecting the digital inputs and outputs to a Solid State Relay module mounting board
The digital inputs and outputs can be easily connected to industry standard I/O module ("brick") mounting boards using the "RACKIO" connector. This connector will mate with common industry standard interface ribbon cables available from the manufacturers of the mounting boards. The mating connector is a 50 pin (2 row by 25 pin) female IDC header connector.
The +5 needed to operate the LED's on an I/O mounting board can be obtained from the SBC-1, either by wiring the connections discretely, or using the connection in the ribbon cable.
The IOSEL jumpers for IO1-IO24 should be set according to which modules are installed and whether they are input or output modules. They should be in the upper position for input modules and lower position for output modules.
Powering the SBC-1 with DC power through the terminal blocks
If you do not wish to use a wall-block transformer to power the SBC-1, a separate 9 to 11 volt DC supplying 400 MA or more, regulated or unregulated power supply can be used to power the unit through the terminal block connections.
Powering the SBC-1 in this manner gives you the advantage of having a DC voltage source available for connection to external devices.
Powering the SBC-1 with AC power through the terminal blocks
If you do not wish to use a wall-block transformer to power the SBC-1, a separate 12 to 13 volt AC at 400 mA or more power supply can be used to power the unit through the terminal block connections. A common 12.6VAC transformer is a suitable source of power.
Powering the SBC-1 in this manner gives you the advantage of having an AC voltage source available for connection to external devices.
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