Diablo Controls DSP-50, Руководство пользователя

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DSP-50 User Manual Page 8 of 27 DSP50_MAN_A
4. Features and Functions
Solid-State Outputs
The DSP-50 has three solid-state (open-collector) outputs. Solid-state outputs have several advantages over
relay outputs:

Allows for a smaller form factor

Lower power consumption

Outputs do not have to be debounced (relay contact bounce when closing)

Higher reliability due to no moving parts
But they also have their limitations:

Requires that the detector and the operator have the same DC common

Requires a pull-up resistor to function correctly

The output can only be pulled down to DC common (can only sink current)

Limited current switching capability (200 milliamps)

Polarity sensitive (will not work if connected backwards)
With proper engineering these limitations can be easily overcome and the benefits of the solid-state output can
be fully realized. Almost all operators are now designed to share their DC common with external devices and
have built in pull-up resistors on their inputs to facilitate working with solid-state (open-collector) outputs.
These inputs usually require less than 20 milliamps of current sinking capability to be activated.
The polarity issue is handled by the operator if the detector plugs directly in to the operator. If using an adapter
board like the RK-1 or RK-3, the negative side of the output is already connected to DC common. So the output
is simply connected to the desired termination point on the controller and it should all work.
The three outputs that are available on the DSP-50 are Output A, Output B, and Output B Inverted. The
operation of Outputs A & B are discussed in the following sections. Output B Inverted is always the opposite of
Output B. This means that if Output B is active Output B Inverted is not and if Output B is not active then Output
B Inverted will be. Output B Inverted will not be mentioned outside of this section, as it is always the opposite
of Output B.
The easiest way to envision the function of a solid-state (open-collector) output is to think of it as a normally
open relay contact with the relay common connected to DC common. In this way, Output A and Output B can
be envisioned as normally open contact closures and Output B Inverted as a normally closed contact.
Detector Reset
When any of the DIP switches or the 10-position rotary switch is changed, or power is cycled to the detector, the
detector will perform a reset. The reset event will last for two seconds while the detector initiates any changes
and waits for all systems to stabilize.