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1. Open the unit by gently inserting a screw driver between the DB-25
connector and the lip of the plastic case (see below). You don't have to
worry about breaking the plastic, but be careful not to bend the D-sub
connector.
Once the unit has been opened, you will be able to see the
terminal blocks located at the rear of the PC board.
2. Strip the outer insulation from the twisted pairs about one inch
from the end.
3. Strip back the insulation on each of the 2 twisted pair wires
about .25".
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4. Connect one pair of wires to XMT+ and XMT- (transmit positive
and negative) on the terminal block, making careful note of which color
is positive, and which color is negative.
5. Connect the other pair of wires to RCV+ and RCV- (receive
positive and negative) on the terminal block, again making careful note
of which color is positive, and which color is negative.
Ultimately, you will want to construct a two pair cross over cable that
makes a connection with the RS-422 device as shown below:
6. If there is a shield around the telephone cable, it may be
connected to "G" on the terminal block. To avoid ground loops, we
recommend connecting the shield at the computer end only. A ground
wire is not necessary for proper operation of the Model 1010A.
7. When you finish connecting the wires to the terminal block, the
DCE
DTE
assembly should resemble the diagram below:
XMT +
XMT -
G
To Shield (Optional)
RCV -
RCV +
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}
RCV+
One Pair
RCV -
G
XMT -
}
One Pair
XMT +
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