Alkeria NECTA Series - Power Selection; I;O Module; Input Module Structure; IO Power Supply Selection

4. Interfacing to the world 46
If you need to build your own I/O cables, please use a good cable featuring a braid whose shielding co-
efcient is greater than 85 %, and connect the external braid shielding to the connector body. The max-
imum allowed length for the I/O cable is 10 m; it is recommended to use the shortest cable allowed by
your application, see Section 2.3 for the available lengths.
Caution
Using cables not properly assembled may damage both the camera and con-
nected devices.
4.2 POWER SELECTION
NECTA can supply to an external device up to 300 mA at 3.3 Vdc or 5 Vdc. User can select between
those two power level using the following code example:
Example Code 4.1 | IO Power Supply selection
if(device.PIOHighVoltageOutAvailable)
device.PIOHighVoltageOut = true;
To select 5 V power voltage, set the PIOHighVoltageOut property to True.
Caution
While booting, NECTA does not supply any power through the I/O. Once
booted, the PIOHighVoltageOut is set to False (default value). Be sure that
behavior will not damage the external hardware.
4.3 I/O MODULE
The signals available through the I/O connector natively support the RS-422 differential signaling and
can also be used in RS-644, LV-TTL/LV-CMOS and 12 V - 24 V single ended signaling (where available).
The NECTA family uses differential transceivers (p/n LTC2855-LTC2865, manufactured by Linear Tech-
nology); to access any data not shown below, refer to the manufacturer’s datasheet.
4.3.1 Input module structure
Figure 4.4 - 4.5 shows the internal structure of a NECTA input module. An input internal termination
can be enabled by software, replacing external end-of-line termination resistors; the input also features
a voltage divider polarizing the ”-” input to support single ended signaling (see Section 4.3.1.5).