Vector Graphic Bitstreamer II, User Manual, Page: 28 / 54

To connect a serial channel to an external peripheral, plug the male
16-pin connector of a Bitstreamer II serial I/O cable into the l5-pin socket
of the desired
serial channel, on the right side of tl1eboard. Then, in
most cases connect the OB-25 socket at the end of this cable to the
peripheral, using a 25-wire flat ribbon cable. Details (and exceptions) are
as follows:
Table 2 names the l5-pin socket corresponding to each channel. Always
insert the connector so that the ribbon cable emerges toward the ~ of the
board. You can double check t.."is by checking that the "l" on the connector
corresp:mds with the "l" printed on the board next to the socket. Then
install the 08-25 at the other end of t.."e cable into one of the available
sockets at the rear of the computer, or 'Nherever convenient.
The board comes with one serial I/O cable. Vector Graphic will supply
additional cables when ordered.
Many RS-232C serial terminals and printers, particularly those working at
1200 baud or less, require none of the RS-232C handshaking lines. Some
requi re that one of these handshaking lines be held at +12 VOC. In eit.'er
case, you can plug these peripherals directly into the 08-25 at the end of
the serial I/O cable without modifying the board at all, because th~ board
holds the most CO~1un handshaking lines at +12 VDC - lines 5, 5, and 8.
Note that the Bitstreamer II does not require any handshaking signals from
the peripheral in order to operate. ----
If you are not sure whether the board will work without modification, try
it before attempting to add additional handshaking signals. Generally, to
IMke sure that you are connecting all the necessary lines, use a 25-wire
ribbon cable between the D8-25 at the end of the serial I/O cable and the
OB-25 connected to the peripheral. The Bitstreamer II board does not
generate ~~desired inhibiting signals on any of the lines.
If a 25-wire cable is not possible, then attempt the connection using
three wires, connecting RS-232C lines 2, 3, and 7 from the DB-25 at t.'eend
of the serial I/O cable to the same pins on the 08-25 which plugs into the
peripheral. (Receive-only printers that do not generate acknowledgement
signals, such as Teletype or Decwriters, do not require connecting line 2.
It is never necessary to connect line 1 - protective ground - because the
Bitstreamer I does not ground it.) If this does not work, then the
peripheral may require one of the RS-232C handshaking lines. The
tlrlO
most
comm:m RS-232C handshaking lines required by serial peripherals are Clear to
Send (line 5) and Data Set Ready (line 6). On some occasions, Received Line
Signal Detector (line
8)
may be required. These three lines are held at +12
VDC by the Bitstreamer II board. The manual for your peripheral should
specify if any are required. To connect one or more, simply connect a wire
between the corresponding desired 2in numbers on the DB-25's at both ends of
your external cable, in addition
to the three lines (2, 3, and 7) given
above. Remember that you do not have to worry about this if you simply use
a 254¥ire ribbon cable.