Camera GPIO Ports and Schematics

The general purpose input/output (GPIO) port on the back of all Emergent cameras carries the GPIO input and output (IO) signals as well as 12 VDC power and ground signals from the power adapter. 

IMPORTANT: Connect only Emergent supplied or approved power adapters to the camera. Other power adapters could permanently damage the camera.

Note: Eros cameras support power-over-Ethernet (POE), so you can power them through the RJ45 port instead of the GPIO port.

There are three variations of the GPIO port. All of them are compatible with the Emergent power adapters and IO accessories.

• Line-scan camera GPIO with 12 pins
• Area-scan camera GPIO with 12 pins
• Area-scan camera GPIO with 8 pins

Looking into the back of a camera, the 12-pin GPIO port has the following pin numbers and wire colors:

Figure 1: 12-pin GPIO port pin numbers and wire colors

Note: The wire colors indicate the color of the wires in the break-out cables that some Emergent power adapters provide.

Looking into the back of a camera, the 8-pin GPIO port has the following pin numbers and wire colors:

Figure 2: 8-pin GPIO port pin numbers and wire colors

Line-scan camera GPIO pinout

Emergent’s line-scan cameras have 12-pin GPIO ports with the following pinout:

1. VEXT: External 12 VDC Power (pins 1 and 2 are connected internally)
2. VEXT: External 12 VDC Power (pins 1 and 2 are connected internally)
3. GPO_0: General Purpose Opto-Isolated Output
4. ENC_A_P: Encoder Channel A, RS422 Positive (LTC2855 Pin 11)
5. ISO_GND: Isolated Ground (reference ground for Opto-Isolated IO)
6. ENC_A_N: Encoder Channel A, RS422 Negative (LTC2855 Pin 10)
7. GPI_1: General Purpose Opto-Isolated Input
8. GND: Ground (pins 8 and 9 are connected internally)
9. GND: Ground (pins 8 and 9 are connected internally)
10. ENC_B_P: Encoder Channel B, RS422 Positive (LTC2855 Pin 11)
11. GPI_2: General Purpose Opto-Isolated Input
12. ENC_B_N: Encoder Channel B, RS422 Negative (LTC2855 Pin 10)

‍Note: The camera’s LTC2855 integrated circuit is a 20 Mbps RS485/RS422 transceiver used on the line-scan encoder inputs.

Area-scan camera GPIO pinouts

Most of Emergent's area-scan cameras have 12-pin GPIO ports but the Eros cameras have 8-pin GPIO ports.

Area-scan camera GPIO with 12 pins

Emergent’s area-scan cameras with 12-pin GPIO ports have the following pinout:

1. VEXT: External 12 VDC Power (pins 1 and 2 are connected internally)
2. VEXT: External 12 VDC Power (pins 1 and 2 are connected internally)
3. GPO_3: General Purpose Opto-Isolated Output
4. GPI_2: General Purpose Opto-Isolated Input
5. ISO_GND: Isolated Ground (reference ground for Opto-Isolated IO)
6. GPO_1: General Purpose Opto-Isolated Output
7. GPO_0: General Purpose TTL (0-5 VDC) Output (use GND as reference)
8. GND: Ground (pins 8 and 9 are connected internally)
9. GND: Ground (pins 8 and 9 are connected internally)
10. DNC: Do Not Connect
11. GPI_5: General Purpose Opto-Isolated Input
12. GPI_4: General Purpose TTL (0-5 VDC) Input (use GND as reference)

Area-scan camera GPIO with 8 pins

Emergent’s area-scan cameras with 8-pin GPIO ports have the following pinout:

1. VEXT: External 12 VDC Power
2. GPI_2: General Purpose Opto-Isolated Input
3. GPO_1: General Purpose Opto-Isolated Output
4. GPO_0: General Purpose TTL (0-5 VDC) Output (use GND as reference)
5. GPI_3: General Purpose TTL (0-5 VDC) Input (use GND as reference)
6. GPI_4: General Purpose TTL (0-5 VDC) Input (use GND as reference)
7. ISO_GND: Isolated Ground (reference ground for Opto-Isolated IO)
8. GND: Ground

GPIO schematics

The following simplified schematics show the GPIO IO circuits.

Optically-isolated GPIO circuits

All Emergent cameras have generally the same optically-isolated GPIO IO circuits shown in the following simplified schematics.

Figure 3: Schematic for opto-isolated input circuits

Figure 4: Schematic for opto-isolated output circuits

For the Opto-isolated output on GPO_n ISO pins shown above, choose R (user load) based on the user VCC and the desired output current.

For example, with user VCC = 24 VDC  and output current = 10mA:

R (user load) = 24 VDC / 10 mA = 2.4KΩ

Use a 240mW resistor package.

Transistor-transistor logic (TTL) GPIO circuits

The TTL IO options are provided for those needing a higher performance IO with low delay and jitter compared to the Opto-isolated IO options.

IMPORTANT: For TTL IO, exceeding +5.5 VDC might damage the camera.

All Emergent cameras with 12-pin GPIO ports have generally the same TTL IO circuits. However, those circuits differ from TTL IO circuits in the cameras with 8-pin GPIO ports, as shown below.

Figure 5: Schematic for 12-pin GPIO TTL input circuits

Figure 6: Schematic for 12-pin GPIO TTL output circuits

Figure 7: Schematic for 8-pin GPIO TTL input circuits

Figure 8: Schematic for 8-pin GPIO TTL output circuits

Line-scan encoder input circuits

Figure 9: Schematic for line-scan encoder input circuits