Vanguard Managed Solutions 6500 PLUS DSU Input and Output Signaling, Input Signals

			DSU DIM Installation
DSU Input and Output Signaling
Introduction
	The input and output signaling information is useful as a debugging tool and replaces
	the EIA summary information associated with other DIM types.
Input Signals
	This table describes the input signals.
	NIS		Not In Service—This signal is normally low (L). If no signal is
			received, or the DSU option is in DSU Loopback mode, or if idle codes
			are received, NIS is listed as high (H). This signal is used to determine if
			the other end of the connection is available.
	BPV		Bipolar Violation—This signal is “H” during normal operation. When
			the signal is “L,” it indicates that some type of bipolar violation was
			received by the DSU option. The signal toggles during a DSU loopback
			condition.
	DL		DSU Loopback—This signal is normally “H.” An “L” indicates that a
			DSU loopback mode is entered.
	C+		Positive Sealing Current*— This signal is “H” if the DC current on the
			telephone company interface is not in the positive direction.
	C-		Negative Sealing Current* —This signal is “H” if the DC current on the
			telephone company interface is not in the negative direction. An “L”
			indicates that the DSU option has detected a negative “sealing” current
			and is therefore performing a CSU loopback.
		Note
		When both C+ and C- are “H”, it indicates that no sealing current exists. This is
		often the case when connected to other DSU type hardware. Normally, the signal
		for C+ is “L” when connected to central office equipment (OCU hardware).
Output Signals
	Although you cannot directly access the output signals, they are manipulated by the
	DSU option software and may be useful for informational purposes. The following
	table describes the output signals.
	RS		Reset— This output resets the DSU option hardware. Its normal
			operating state is “H.”
	LL		Local Loopback — When this signal is “L”, the DSU hardware is
			locally looping data back to the 6520 hardware by way of the EIM.
	CL		CSU Loopback —When this signal is “L”, the DSU hardware is looping
			the remote connection's receive to transmit.
	IDL		Idle —An “H” on this signal tells the DSU hardware to send idle bipolar
			violations to the remote system.
	CLK		Clock Mode—The signal “H” denotes the use of the network clock. The
			DSU option provides the clock when this signal is “L.”
	You can view these signals using the control terminal Monitor menu item on the
	Main menu within the CTP in the control terminal.

Installation 2-69