| Excerpt |
|---|
GPIO / Trigger / Strobe Interface
...
 Diagram of basic optocoupler function | An optocoupler is a device using optical path to transfer an electronic signal between two circuits. It basically consists of a photodiode converting the input signal to light and a phototransistor converting the light again to electronic signal. The optocoupler is useful in situations where one part of the circuit needs to be galvanically isolated from the other part to prevent damage or unwanted interference. It is used to prevent ground loops or to block voltage spikes. For effective use of the optocoupler it is important to control it using an independent power supply. When the external circuit is galvanically connected to the camera (eg. when reusing the camera's power to control the optocoupler), the optocoupler's protective function is eliminated. |
Due to the schematic characteristic the signal transmitted through an optocoupler interface will be inverted. For details please see schematic below.
Optocoupler parameters summary
...
The CORSIGHT camerais equipped with four optically isolated input lines. One input optocoupler is fully independent, the other three are connected with a common cathode (Section “I/O connector”) due to limited number of pins on the I/O connector.Each input line is protected by a current limiter circuit.
| Tip |
|---|
The optocoupler input's logical state is understood as logical 0 if no current is flowing through the optocoupler diode, logical 1 if current is flowing through the diode. See schematic below. |
The optocoupler is guaranteed to be switched on (logical 1 input status) when the voltage applied to the input is in range of 5 - 24V (tolerance 10%). It is guaranteed to be switched off (logical 0 input status) when the applied voltage is under 1.5V. The input status is undefined between 1.5V and 4.5V, the input voltage must not exceed the 24V limit!
...
Any of the available optocoupler inputs or TTL inputs can be used for triggering. The input line mapping on the camera connectors is described in section Connector and cable description .
The characteristics and default behavior of these interfaces are described below in Section “Optocoupler interface” and Section “TTL I/O's”. Those sections also provide examples how to connect the inputs.
Schematic
| Warning |
|---|
If the camera serial number has an X or Y in the 9th digit (e.g. 14A2GEBAX2042013) the I/O connector has the Prototype pinout. Expand below! |
| Expand | ||||
|---|---|---|---|---|
| ||||
|
| Tip |
|---|
The schematic of newer cameras I/O interface can be found below. |
|
| Attachments | ||||||
|---|---|---|---|---|---|---|
|
...
| Note |
|---|
The optocoupler output work with operating voltage range of 5-24 V. The maximal switched output current is 100 mA per optocoupler, higher current could damage the optocoupler output circuit. |
Strobe output
Any of the available optocoupler output can be used for strobe control. The output line mapping on the camera connectors is described in section Connector and cable description .
Schematic
| Warning |
|---|
If the camera serial number has an X or Y in the 9th digit (e.g. 14A2GEBAX2042013) the I/O connector has the Prototype pinout. Expand below! |
...