ADTRAN T200 H4TU-R specifications Table A-2. Loopback Control Codes

Table A-2. Loopback Control Codes (Continued)

Function	Code (Hex / Binary)	Response
Span Power Disable1	6767 or	If the units are armed and 6767 is sent from the network, the
	0110 0111 0110 0111	H4TU-C will disable span power. If the pattern is sent from
		the network, the span power will be disabled as long as 6767
		pattern is detected. Once the pattern is no longer received, the
		H4TU-C will reactivate span power. All units will then retrain
		and return to the disarmed and unlooped state.
First H4R Loop Up 1,2	C741	If one or more H4Rs are present, the H4R closest to the
	1100 0111 0100 0001	H4TU-C will loop up toward the network, 2 seconds of AIS
		(all ones) will be transmitted, the looped data will be sent for 5
		seconds, and then a burst of 10 logic errors will be injected.
		The burst of 10 logic errors will continue every 20 seconds as
		long as the C741 pattern is detected. When the pattern is
		removed, the unit will remain in loopback. If the pattern is
		reinstated, the injection of 10 logic errors will continue every
		20 seconds.
Second H4R Loop Up 1,2	C754	If two H4Rs are present, the second H4R from the H4TU-C
	1100 0111 0101 0100	will loop up toward the network, 2 seconds of AIS (all ones)
		will be transmitted, the looped data will be sent for 5 seconds,
		and then a burst of 200 logic errors will be injected. The burst
		of 200 logic errors will continue every 20 seconds as long as
		the C754 pattern is detected. When the pattern is removed, the
		unit will remain in loopback. If the pattern is reinstated, the
		injection of 200 logic errors will continue every 20 seconds.
H4TU-R Address 20 for	C742	If armed, the H4TU-R will loop up toward the network, 2
Extended Demarc 1,2	1100 0111 0100 0010	seconds of AIS (all ones) will be transmitted, the looped data
		will be sent for 5 seconds, and then a burst of 20 logic errors
		will be injected. The burst of 20 logic errors will continue
		every 10 seconds as long as the C742 pattern is detected.
		When the pattern is removed, the unit will remain in loopback.
		If the pattern is reinstated, the injection of 20 logic errors will
		continue every 10 seconds.

1.Units must be armed with 11000b or FF48h before this code will work.

2.Loopback and error injection will only occur if the in-band code is received by the unit that is to go into loopback. In other words, if another loopback blocks the in-band code from being transmitted to the unit that is to go into loop- back, loopback and error injection will not occur.

Note: All codes listed above must be sent for a minimum of 5 seconds to be detected and acted upon

A-4 Issue 1, December 2003 61223424L2-5A