Patton electronic 3088RC user manual CONFIGURING THE X.21 REAR CARD, Description, Strap, Function

SGND & FRGND (JB4). In the connected position, this strap links Signal Ground and frame ground through a 100 ohm resistor. In the open posi- tion, signal ground is disconnected from frame ground.

JB4	Description
Position 1&2	SGND and FRGND Connected
Position 2&3	SGND and FRGND Not Connected

3.7 CONFIGURING THE X.21 REAR CARD

The X.21 interface card is conÞgured by setting the conÞguration straps located on the PC board.

Model 1001RCM11545& 1001RCM115TB Strap Settings

Figure 3 shows strap locations for the Model 1001RCM115XX (DB-15) rear cards. These straps determine various grounding characteristics for the terminal interface and twisted pair lines. JB3 and JB4 are user con- Þgurable.

JB3 1 2 3

JB4

1 2 3

Figure 3. 1001RCM115XX strap locations

The table below provides an overview of interface strap functions for the rear interface cards. Following the table overview are detailed descrip- tions of each strap’s function.

Strap	Function	Position 1&2	Position 2&3
JB3	DTE Shield (Pin1) & FRGND	Connected	Open*
JB4	FRGND & SGND (Pin 8)	Connected	Open*

* Indicates default setting

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