GEViCAM GP-151400, Operation Manual

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4.6.3 GPIO Input and Output
•
TTL Input and Output
The Trigger Input and Strobe/Exposure Control
Pulse Out are TTL input and output. The simplified
input and output circuits are shown in Fig. 57.
It is a typical high-speed inverter-buffer IO and the
sink current is not high (24 mA). Therefore, a care
must be taken for these interface ratings. Although
the internal logic has ability to reject the induced
noise but TTL is high impedance in general and
avoiding the noise into the interface is a good
practice. We suggest using full functional cables
which have multiple individually shielded cables to
meet the noisy environment applications.
•
Opto-isolated IO
We use a quad opto-isolator and a set of input/
output, two sets of input or two sets of output are
selectable with solder jumpers.
A full function GPIO cable has four twisted pair of
cables. Opto-isolated IO connects to each differen-
tial pair IOs. User can select the following pairs;
1 D1 Input, D2 Output (Default)
2 D1 Input, D2 Input
3 D1 Output, D2 Output
4 D1 Output, D2 Input (Fig. 58)
Hardware jumper change besides software selec-
tion is required. See 3.4.2.
The Maximum rating of LED I
F
is 50 mA and the
minimum current to turn the transistor ON is 3 mA.
This allows the overall input voltage range of 3.0V
to 50V. (We recommend to stay up to 28V DC).
Output is open collector. Photo-transistor rating is
V
CEO
= 80V and the maximum current is 50 mA.
Operating temperature range is –55 to 100
°
C. The collector resistor, Rc is decided to achieve 3mA
to 5mA of Ic at the operating voltage (Vcc). (For Vcc= 24 V , Rc = 24V/5mA = 4.8 (or 4.7)K
Ω
.)
The isolation resistance is 10
14
Ω
and the isolation voltage is 5000V DC and 2500V AC.
For the detail of opto-isolator, please refer TLP281.
•
RS-485
The RS-485 is twisted pair serial communication standard, which can run over 1000 feet. We use
ISL81486 ultra high speed RS-485 transceiver, which is compatible with PROFIBUS. The speed
can go 30 Mbps. The termination resistance between the differential IOs is 120
Ω
.
•
CAN Device
By replacing the RS-485 IC, CAN device is available. The device is SN65HVD251. The device can
be used in CAN, DeviceNet or SDS applications.
•
Audio CODEC
The audio codec uses AD74111, monaural digital audio IC.
For the specific CODEC characteristics, please refer the AD74111 data sheet.
GEViCAM Inc
Fig. 57
Fig. 58