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Note the following cabling information for this wiring guide:
•
Only two pairs of wires are used in the 8-pin RJ 45 connector to carry Ethernet signals.
•
Even though pins 4, 5, 7 and 8 are not used, it is mandatory that they be present in the cable.
•
10BaseT and 100BaseTx use the same pins, a crossover cable made for one will also work with
the other.
•
Pairs may be solid colours and not have a stripe.
•
Category 5 cable must use Category 5 rated connectors.
The maximum cable run between the downstream keyer and the supporting hub is 300 ft (90 m). The
maximum combined cable runs between any two end points (i.e. downstream keyer and PC/laptop via
network hub) is 675 feet (205 m).
Devices on the Ethernet network continually monitor the receive data path for activity as a means of
checking that the link is working correctly. When the network is idle, the devices also send a link test
signal to one another to verify link integrity. The downstream keyer rear panel is fitted with two LEDs to
monitor the Ethernet connection.
10/100:
This Amber LED is ON when a 100Base-TX link is last detected. The LED is
OFF when a 10Base-T link is last detected (the LINK LED is ON). Upon power-
up, the LED is OFF as the last detected rate is not known and therefore defaults
to the 10Base-T state until rate detection is completed.
LN/ACT:
This dual purpose Green LED indicates that the HD9626DSK has established a
valid linkage to its hub, and whether the HD9626DSK is sending or receiving
data. This LED will be ON when the HD9626DSK has established a good link to
its supporting hub. The ON LED is a good indication that the segment is wired
correctly. The LED will BLINK when the HD9626DSK is sending or receiving
data. The LED will be OFF if there is no valid connection.
2.7.
CONNECTING THE GENERAL PURPOSE INPUTS AND OUTPUTS
Figure 2-2 shows a simplified schematic diagram of the GPIO circuitry. The user can connect GP+3.3V
supplied from the keyer unit into the Vext pin to provide power to the GPIO Opto-isolator circuitry. In
this configuration the user can activate GPIs simply by connecting the GPI input pins to Ground (see
Figure 2-3). This can be done with a button, switch, relay or an open collector transistor. The GPO's
are active low and require an external pull up resistor (see Figure 2-5). 3.3 volts is available to the user
to be used for driving external circuitry. Care must be taken to limit the load to 0.5W so there is no
affect on the power supply source on the unit.
Warning: Do not connect GP+3.3V from one unit to another unit's GP+3.3V
output.
INSTALLATION
HD9626DSK Instruction Manual
Revision 1.4
Page 2-7
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