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IMACS System Release 5.1.9
Reference Guide
Model No.
Running Head
Data Modules and Applications
Applications
•
The 820360 HSU Trunk Card supports two V.11/X.21 data ports The ports may be
configured as user ports, or can be used as externally clocked network interface ports.
•
The 821260 HSU card supports two “true” V.35 synchronous data ports.
•
The 821360 HSU Card provides two ports. Each port can be individually configured to
support RS530 or V.35 devices. The 821360 also supports V.25bis dialing commands (an
in-band dialing protocol) and RS366 dialing through the use of separate DB-15 pin
RS366 port connectors on the rear of the card. The 821360 also has a proprietary in-band
performance monitoring system.
•
The 821460 HSU card supports two (2) V.35 synchronous data ports. The ports may be
configured as user ports, or can be used as externally clocked network interface ports.
•
The 821570 HSU card provides four ports which can be individually configured to
support RS530, RS449/422, and V.35. devices.
•
The 821660 HSU card provides four-ports which support four EIA530/A or V.35 data
ports. The selection EIA530, EIA530A, or V.35 is made on a port-by-port basis using
on-board switches. This enhanced HSU card is a derivative of the 821570 card, with
better clock performance, a true V.35 interface and a receiver clock invert option.
Each port on a HSU can be independently configured to operate at speeds of Nx56 or Nx64
Kbps, where N equals 1 to 24 in T1 mode or 1 to 31 in E1 mode. In addition to the data rate,
each synchronous port’s Transmit Clock can be programmed for Internal or External modes
and both the Clock and Data Polarity may be inverted through software.
The External Transmit Clock mode and the Inverted Clock Polarity mode may be useful in
ensuring that both the Transmit Clock and the Transmit Data are in sync when they reach the
HSU port.
This should occur when the HSU port and the attached device are connected over a long cable.
The Data Polarity may be inverted to ensure the density for Nx64 Kbps data circuits
supporting HDLC-based protocols that are connected to non-B8ZS T1 facilities.
The “Clear To Send” control lead may always be set to high, low or local mode. In local mode,
the CTS signal reflects the state of the Request To Send (RTS) signal that is received from the
attached DTE device. In that mode, the delay between RTS and CTS is software set-able, with
options of 0, 30, 60 or 100 milliseconds. Additionally, if the HSU port is programmed to
operate at Nx56 Kbps, then RTS will be transmitted end-to-end and presented as RLSD at the
far end of the circuit.
Software-initiated diagnostics support include the setting of local loop backs towards either
the network or the attached DTE equipment. Additionally, a remote loop back function allows
the HSU card to generate three DDS-compatible latching loop back codes for the far-end
OCU, CSU and DSU equipment. Similarly, the HSU data port may be programmed to detect
and respond to both latching and non-latching DDS-format OCU, CSU and DSU loop back
codes initiated from the remote end of the circuit. A time-out option authorizes the HSU port
to automatically release the loop back after ten minutes. This feature applies to an HSU port
that is running at 56 Kbps or for super-rate circuits if the loop back code is transmitted in the
