Vanguard Managed Solutions Vanguard 6500 PLUS - Manual (Page 77)

Installation 2-69
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.
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.
You can view these signals using the control terminal Monitor menu item on the
Main menu within the CTP in the control terminal.
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.
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.”