Card Type	E1 CSU/DSU
Chip Set	Unidentified
Transfer Rate	2.048Mbps
Data Bus	External

CONNECTIONS
Function	Label	Function	Label
75 ohm coax line in or out	CN1	120V or 230V AC power	CN5
120 ohm shielded twisted pair	CN2	Fuse for 120V: 250V @ 50mA Fuse for 230V: 250V @ 32mA	F1
75 ohm coax line in or out	CN3	Power switch	SW1
V.35, V.36, or X.21 port via UD-26	CN4	Local analog loopback test switch	SW2
Note:The information as to which coax connector is for transmit and which is for receive is unidentified.

USER CONFIGURABLE SETTINGS
Setting		Label	Position
»	Shield of transmit coax is not grounded	LK1	Open
	Shield of transmit coax is grounded	LK1	Closed
»	Shield of receive coax is not grounded	LK2	Open
	Shield of receive coax is grounded	LK2	Closed
»	Clock master mode disabled	LK3	Open
	Clock master mode enabled	LK3	Closed
»	Shield of twisted pair is not grounded	LK4	Open
	Shield of twisted pair is grounded	LK4	Closed
»	Auto-detect device connected to line in	LK5	Closed
	Do not auto-detect device connected to line in	LK5	Open
»	DSU is clock master	S1/1	On
	DSU is clock slave	S1/1	Off

USER CONFIGURABLE SETTINGS (CON’T)
Setting		Label	Position
»	Loopback mode is enabled only by front panel switch	S1/4	Off
	Loopback mode is enabled continually	S1/4	On
»	Transmitted and received data are not inverted	S1/5	Off
	Transmitted and received data are inverted	S1/5	On
»	Power supply set for 230V operation	SW3	Off
	Power supply set for 115V operation	SW3	On
Note:Setting LK3 to Open overrides S1/1. When LK3 is closed, the DSU may still be set to Slave mode with S1/1.

LINE TERMINATION IMPEDANCE
Setting	LK6	LK7
75 ohm	Closed	Closed
120 ohm	Open	Open

LINE SPEED
Setting	S1/2	S1/3
256Kbps	On	On
512Kbps	Off	On
1.024Mbps	On	Off
2.048Mbps	Off	Off

CLOCK SOURCE
Setting	S1/6	S1/7
External clock source	On	On
Internal clock source	Off	Off

SERIAL PORT TYPE
Setting	S1/8	S5/1	S5/2	S5/3	S5/4	S5/5	S5/6	S5/7	S5/8
V.35	N/A	On	On	On	On	On	On	On	On
V.36	On	Off	Off	Off	Off	Off	Off	Off	Off
X.21	Off	Off	Off	Off	Off	Off	Off	Off	Off

SERIAL PORT TYPE (CON’T)
Setting	S6/1	S6/2	S6/3	S6/4	S6/5	S6/6	S6/7	S6/8
V.35	On	On	On	On	On	On	On	On
V.36	Off	Off	Off	Off	Off	Off	Off	Off
X.21	Off	Off	Off	Off	Off	Off	Off	Off

DIAGNOSTIC LED(S)
LED	Color	Status	Condition
LED1	Green	On	Power is on
LED1	Green	Off	Power is off
LED2	Green	On	DSU is receiving valid signal
LED2	Green	Off	DSU is not receiving valid signal
LED3	Green	On	DSU is operating as master clock source
LED3	Green	Off	DSU is operating as slave clock source
LED4	Red	On	DSU is in loopback test mode
LED4	Red	Off	DSU is not in loopback test mode