Envoy ACP/XF Configuration and Management Manual

Introduction to EnvoyACP/XF
EnvoyACP/XF Configuration and Management Manual—429232-003
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ServerNet WAN Concentrator
ServerNet WAN Concentrator Features
The ServerNet WAN concentrator supports:
•
Six half-duplex or six full-duplex lines for each ServerNet WAN concentrator
•
Bit-oriented devices using the HDLC, SDLC, or ADCCP protocols
•
Bell 201, 208, 209, or 212 modems (or equivalents)
(All of these modems must be strapped to provide external clocking; also the 212-
type modem must be strapped for synchronous operation.)
•
Conversion of ASCII code to EBCDIC code, and EBCDIC to ASCII
•
Automatic polling of multipoint tributary stations
•
Point-to-point or multipoint transmission modes
Multipoint Polling
In NRM multipoint configurations, the ServerNet WAN concentrator also handles some
polling functions.
When used as the supervisor station, the ServerNet WAN concentrator manages the
polling of the lines. EnvoyACP/XF passes a polling list created by the user to the WAN
subsystem, and polling begins. (See the EnvoyACP/XF Application Programming
Manual for further information on polling.)
The ServerNet WAN concentrator is interrupted when text is received from a polled
station, when polling is stopped, or when the poll list is exhausted.
When used as a tributary station, the ServerNet WAN concentrator recognizes when its
lines are polled or selected. For each line, EnvoyACP/XF stores up to two distinct
secondary addresses. EnvoyACP/XF uses incoming frames containing the specified
addresses to satisfy outstanding read requests and discards other frames.
EBCDIC Translation
The WAN subsystem’s internal character code is always ASCII. However, you can
configure the line characteristics to translate to EBCDIC (on output) and from EBCDIC
(on input) for communicating with an EBCDIC-based computer. You can also configure
the line characteristics to begin and end the code translation anywhere within the
frame’s information field. That is, header and trailer information can be passed without
translation even though the embedded data is translated. The relevant configuration
attributes for EBCDIC translation are TRANSLATE, TRNSLENGTH, and
TRNSOFFSET.