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".

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:

XMT +

 

RCV+

}One Pair

XMT -

 

RCV -

G

To Shield (Optional)

G

 

RCV -

 

XMT -

 

RCV +

 

XMT + }One Pair

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 assembly should resemble the diagram below:

+RCV-

G-XMT+

6

7

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Patton electronic 1010A user manual Xmt + Rcv+, Rcv Xmt Rcv +