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Page 13
Installation
Switch S3-6: RS-232 Initiation of Remote Loopback Test
The setting for switch S3-6 determines whether or not the ME475A-R2’s remote digital
loopback test can be initiated by raising pin 21 on the RS-232 interface.
Switches S3-7 and S3-8: Anti-stream Control
Switches S3-7 and S3-8 are set in combination to determine the time out period for the
ME475A-R2’s anti-stream control timer.
3. INSTALLATION
The ME475A-R2 operates in four twisted pair topologies: 2-wire/point-to-point, 2-
wire/multipoint, 4-wire/point-to-point, and 4-wire/multipoint. In each of these topolo-
gies, the twisted pair wire must be 19 - 26 AWG “dry”, unconditioned metallic wire (see
Appendix C for wire recommendations). Dial-up analog circuits, such as those used
with a standard Hayes-type modem, are not acceptable. The twisted pair may be
shielded or not shielded. Both types yield favorable results.
The ME475A-R2 offers two methods of twisted pair connection: RJ-45 jack and termi-
nal blocks. Figure 3 shows the location of these interfaces on the rear panel of the
ME475A-R2. Connect the wire to each ME475A-R2 as described in the instructions
that follow the illustration. The “+” and “-” indicators are for reference only. The
ME475A-R2 is not sensitive to polarity.
Off
RS-232 initiation disabled
S3-6
Setting
On
RS-232 initiation enabled
Off
RS-232 initiation disabled
S3-7
S3-8
Setting
Off
Off
Disabled
Off
On
12.5 seconds
On
Off
50.0 seconds
On
On
12.5 seconds
S3-5
Setting
Summary of Contents for ME475A-R2
Page 1: ...ME475A R2 Async Sync Short Haul Modem...
Page 32: ...ME475A R2 version 1...
