CMU Communicator

ER-8 Wiring HOWTO

1 main | 2.1 requirements | 2.2 install | 3.1 manuals | 3.2 quick guide | 4.1 downloads | 4.2 quick fixes | 5 links
Attached you should find a picture of the inside of the ER-8 box.  
You should read this message using a fixed pitch font.

ER-8 wiring

There is a male DB-25 connector at the unseen end of the
grey cable pictured at the bottom.  There is also a 10 conductor
ribbon cable attached to the blue connector.  The conductors
from left to right are denoted rc1 ... rc10

The pinout of the DB-25 connector is given in the
following table:

db-25  ER-8 ribbon & relay block

DB(1) -> NO1 (first relay)
DB(2) -> NO2 (second relay)
DB(5) -> COM1 (first relay)
DB(14) see diagram below
DB(15) see diagram below
DB(18) -> COM2 (second relay)
DB(19) see diagram below
DB(20) see diagram below
DB(21) rc10

One side of the resistors are
all connected and that side is connected
to rc9.  The other side of each resistor is
connected to a ribbon cable conductor and
a DB-25 pin as show.

DB(14) DB(15) DB(19) DB(20)
^      ^      ^      ^
|      |      |      |
rc7<-+ rc5<-+ rc3<-+ rc1<-+
|      |      |      |
R      R      R      R    R = 10K Ohm resistor
|      |      |      |
rc9 <----+------+------+------+

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