|
Digital Output Soft-Devices
Digital Output Soft-DevicesSoft-I/O is unique in its ability to handle Inputs and Outputs. Inputs bring sensors into Soft-I/O. Outputs provide the action of the control system. Digital outputs supply power to actuate devices connected to Soft-I/O. Digital outputs can provide power at either 5 volts or 24 volts. Why are there different types of digital outputs? After all, with a PLC, "all digital outputs are digital outputs". Well, that's not exactly correct. With a PLC, you have to know if your output is sourcing or sinking. You have to buy the right output module to handle those different ones. And you have to know the voltage of the output. Not with Soft-I/O. But Soft-I/O goes beyond the idea of "digital output". After all, a light bulb is a very different DEVICE than a mechanical relay. You might want to dim a light bulb by using PWM (Pulse Width Modulation). You can't do that with a relay. And a relay coil is an inductor which has a very different electrical behavior than a light bulb. Bottom line, Soft-I/O knows how to handle our digital outputs at a device level. Let's learn more! Overview If you cannot find a Soft-Device suitable for your digital output, you may want to choose the Versatile Digital Output Soft-Device. For example, let's assume that you want to drive a large electric heater for an incubator in a bio-tech system. You will probably use a solid state relay to drive the heater and employ Pulse Width Modulation (PWM). It does not make sense to use the Relay Soft-Device because your solid state relay is non-inductive. So, you can choose the Versatile Digital Output Soft-Device. OverviewA Solenoid Digital Output Soft-Device is capable of driving a two-wire inductive solenoid. A solenoid is made up of a coil of wire that surrounds a metal part that responds to the magnetic field produced by the coil. The metal part is induced to move in response to the magnetic field. Solenoids are widely used in locks, latches, brakes and other electrically-actuated mechanisms. You may connect the two wires from the solenoid to any two Soft-I/O pins, or you may connect one wire to the same pin as other digital output devices and then connect the second wire to any other Soft-I/O pin, thus saving pins. Your may configure the output pin to source current or sink current. It's up to you. Just make sure that the common is the same level. Or course, Soft-I/O will guide you to make sure that you to not accidentally connect it up incorrectly. It's that simple! OverviewA Relay Digital Output Soft-Device is capable of driving a two-wire inductive relay or contactor (which is a large relay). A relay is made up of a coil of wire that surrounds a metal part that responds to the magnetic field produced by the coil. The metal part is induced to move in response to the magnetic field. The motion of the metal part causes one or more electrical conctacts to "make" or "break" thus completing or interrupting an electrical circuit. You may connect the two wires from the relay to any two Soft-I/O pins, or you may connect one wire to the same pin as other digital output devices and then connect the second wire to any other Soft-I/O pin, thus saving pins. Your may configure the output pin to source current or sink current. It's up to you. Just make sure that the common is the same level. Or course, Soft-I/O will guide you to make sure that you to not accidentally connect it up incorrectly. It's that simple! OverviewA Light Bulb Digital Output Soft-Device is capable of driving a two-wire light source. A light bulb used in industrial controls is generally an LED because of the significantly longer lifetime of an LED compared to a filament-based bulb. The cost difference of an LED compared to a filament-based light bulb is small compared to the cost of bulb failure. Light bulbs are widely used as indicators on panels and enclosures. You may connect the two wires from the light bulb to any two Soft-I/O pins, or you may connect one wire to the same pin as other digital output devices and then connect the second wire to any other Soft-I/O pin, thus saving pins. Your may configure the output pin to source current or sink current. It's up to you. Just make sure that the common is the same level. Or course, Soft-I/O will guide you to make sure that you to not accidentally connect it up incorrectly. It's that simple! OverviewYou might reasonably ask why Soft-I/O contains a separate Soft-Device for a buzzer. The answer goes to the core of the philosophy of Soft-I/O. The answer is, "Because Soft-I/O can!" With a PLC or a conventional old-style I/O system, inputs and outputs are just wires tied to the terminal blocks. With Soft-I/O, the entire device, power and all, is connected to the module. That means that Soft-I/O knows about the device and how to handle it. Lights flash and buzzers beep. But we need to stop buzzers from beeping, so there are various methods of handling devices like buzzers so that you don't have to write software or maintain it! It could not be simpler with Soft-I/O. |