15
CHAPTER 3: Installation and Configuration
6. Set the DIP switch(es) as appropriate for your application. Refer to Table 3-1
and Figure 3-7 below, and keep in mind that OFF = UP and ON = DOWN.

Table 3-1. Possible Settings for Switches S2 and S3

All 25 leads of the Local/Remote Electronic Switch’s DB25 connectors are straight-
through and are isolated from one another. In RS-232 and DB25 parallel applications,
we recommend that you use DIP switches S2 and S3 to make a “common” ground
connection; this will help eliminate intermittent noise problems.
Recommended Settings for RS-232 Applications:
S2 S3
Model(s) Pos. 1 Pos. 2 Pos. 1 Pos. 2 Connection(s) Made
SW980/982 units ON OFF N/A N/A Port C Pin 7 to
(down) (up) Switch ground
SW981 units ON ON OFF OFF Ports AA and BB Pin 7
(down) (down) (up) (up) to Switch ground
Recommended Settings for DB25 Parallel Applications:
S2 S3
Model(s) Pos. 1 Pos. 2 Pos. 1 Pos. 2 Connection(s) Made
SW980/982 units OFF ON N/A N/A Port C Pin 18 to
(up) (down) Switch ground
SW981 units OFF OFF ON ON Ports AA and BB Pin 18
(up) (up) (down) (down) to Switch ground
Recommended Settings for Other Applications:
All models—Set all positions of switches S2 [and S3] to OFF (up).

Figure 3-7. DIP switch S2 of the SW980 and SW982 models (left)

and DIP switches S2 and S3 of the SW981 models (right).

SERIAL PARALLEL
ON 1 2 ON 1 2
SERIALPARALLEL
ON 1 2
(S2)
(S2) (S3)