ADTRAN D4-OCU Connector Pin Assignments Faceplate Indicators, Auto Loop Disconnect, Maintenance

	28	1	FRM GND
	29	2	-12V
+5V	30	3	GND
IN CLK	31	4	+12V
TNEN	32	5	GND
	33	6	TWD
	34	7	TSP
TDATA	35	8	TSQ
RSAB
	36	9	RNPCM
	37	10	RFA
RCLK	38	11	TDCLK
RWD	39	12
RSQ	40	13	RSP
	41	14	RNDIS
	42	15	-48R
-48V	43	16
	44	17
	45	18
	46	19
R1	47	20	T1
	48	21
	49	22	IZ
	50	23
R	51	24	T
	52	25
	53	26
	54	27

Figure 4. Connector Pin Assignments

Faceplate Indicators

The OCU DP has four faceplate LED indicators as follows:.

LOOPBACK	On for OCU or channel loopback.
IDLE CKT	On for inactive data channel. Detects
	the reception of the idle sequence
	from the loop side (DSU/CSU to OCU).
NO SX	On for no sealing current. Indicates
	detection of no sealing current on the
	loop.
AUTO DIS	On for auto disconnect. Indicates a
	loop disconnect due to poor signal
	quality.

5.AUTO LOOP DISCONNECT

On multi-point networks, failure of a single node can cause the entire network to be inoperable. To prevent this, the D4-OCU DP incorporates an auto loop disconnect feature. Loop disconnect occurs when sealing current is absent or the quality monitor threshold is exceeded.

If the quality monitoring option is enabled and poor received signal quality is detected, the loop will be disconnected and abnormal station control code (10011110) will be sent toward the network.

This will cause the branch to be blocked at the next junction (MJU or QMJU). The D4-OCU DP detects poor received signal quality on the loop by monitoring for illegal bipolar violations.

6.MAINTENANCE

The D4-OCU DP requires no routine maintenance to operate properly. In case of equipment malfunction, use the faceplate test connector and indicators to determine the trouble source. The faceplate of the D4-OCU DP contains Bantam test jacks for the KS-20908/20909 or a functionally equivalent test set. All units contain LEDs as described in subsection 4.

ADTRAN does not recommend that repairs be performed in the field. Repair services may be obtained by returning the defective unit to the ADTRAN Repair Department (see subsection 7).

7.WARRANTY AND CUSTOMER SERVICE

ADTRAN will replace or repair this product within ten years from the date of shipment, if the product does not meet its published specifications or if it fails while in service. For detailed warranty, repair, and return information, refer to the ADTRAN Equipment Warranty and Return Policy and Procedure.

Return Material Authorization (RMA) is required prior to returning equipment to ADTRAN. ADTRAN does not recommend that repairs be performed in the field.

For service, RMA requests, or further information, contact one of the following numbers:

ADTRAN Customer Service:
Applications Engineering	(800) 615-1176
(pre-sales support and inquiries)
Technical Support	(800) 726-8663
(post-sales; have unit serial number available)
Sales	(800) 827-0807
RMA (Repair Service)	(205) 971-8722

Repair and Return Address:

ADTRAN, Inc.

Customer Service Department

901 Explorer Boulevard

Huntsville, Alabama 35806-2807

4 Section 61107005L2-5, Issue 3 61107.005L2-5C