Phytec eGrabber-4plus, Руководство по оборудованию

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eGrabber-4plus
18 
PHYTEC Meßtechnik GmbH 2004 L-608e_4
Caution:
The polarity of the connected voltage must be selected so that the
I/O pin 26 (X3) or 15 (X6) has a constant positive potential.
Negative potential (i.e. Ground) at pin 26 or 15 can lead to destruction
of the Grabber card!
While using the output function (I/O-Pin to Ground), the operating
voltage must be b5 V and +28 V. When using the I/O pin as
input, the operating voltage must not exceed 28 V.
The I/O-Pin is not galvanically isolated from the video lines, the CPU
or the remaining signal lines.
1.7 I
2
C Interface
External devices can be polled or controlled via the I²C interface. In
order for this to occur, the external devices must have an I²C interface
operating in Slave mode.
The I²C interface is available at pin header row X3, and is also
available on the internal pin header row of the Option Port X6
(also see section 1.8). It is possible to connect multiple I²C devices to
the bus, but these devices must be distinguished by their device
addresses.
Table 6 shows the relevant pin assignment of the pin header rows.
Pin Header Row X3 Pin Header Row X6
Pin Function Pin Function
21 I²C Bus: SDA 18 I²C Bus: SDA
22 I²C Bus: SCL 17 I²C Bus: SCL
23 Ground 19 Ground
Table 6: Connecting the I²C interface to Pin Header Rows X3, X6
Note:
The maximum cable length is restricted, due to the fact that the I²C
interface is driven by TTL signals. For a connected device, depending
on the configured transmission rate, the maximum cable length is
aprox. 1 - 2 m.
Use cables with sufficient shielding when connecting this device.