HP 27140A Hardware Reference Manual page 6

6
Preface
This manual describes the HP 27140A Asynchronous 6-Channel Multi-
plexer Interface Card with Modem Control. This multiplexer is used in
HP 9000 Series 500 computer systems.
The multiplexer accesses up to six remote or local terminals conforming to
EIA specifications RS-232-C or
ccrrr
recommendations V.24 and V.28.
These protocols are designed specifically for use with modems to transmit
data over telephone networks worldwide. (CCITI V.24 is the signal
naming and specification recommendation, and CCITI V.28 is concerned
with the electrical characteristics of those signals.)
To ensure proper installation and operation, use
this
manual along with
the instructions found in the computer system manuals.