Specifications

Page 22–6
FOCUS System Manual
the male connector, refer to the pin assign-
ments in Figure 22-8.
The SRD-2 Module interface consists of four
DB9 female connectors at the end of an 18"
cable, as shown in Figure 22-2. This cable is
connected to the interface board via a DB25
Male connector. The connectors have
threaded standoffs so that you can secure the
cable you are connecting. We recommend you
use RS-232C cable with an outer shield. To
protect against applied transients, you should
ground the shield to the base terminal chassis
ground. The SRD-4 includes a compression
type terminal block for the RS485 connection.
The RS232 connections are made via 18"
cables with DB9 connectors labeled "A", "B",
"C", & "D".
The equipment (e.g., modem, event recorder,
microcomputer) you attach to the module
should be no more than 50 feet away.
22.3.2 Software Settings
There are no configurable settings for the SRD
Module, except for the DS1 time-slot assign-
ments. The SRD is a transparent module (i.e., it
does not process the data passing through it).
22.4 Specifications
The SRD Module's technical specifications are
shown in Tables 22-3, 22-4 & 22-5.
22.4.1 Status Indicators
This module has nine status indicators, as shown
in Figure 22-7. The red/green status LED is green
if the module is functional and red if the module is
non-functional. The green "TX" LED, when lit for
either channel, indicates that the module is trans-
mitting data on that channel. The green "RX"
LED, when lit for either channel, indicates that the
module is receiving data on that channel.
22.5 Acceptance Test
As noted earlier, we recommend that you initially
install and test SRD modules in "test" chassis (i.e.,
chassis that are not part of an operating network).
This way, you can quickly perform the acceptance
tests without interfering with a live network.
We recommend that you use the HP 1645A Data
Error Analyzer or equivalent to test the data flow
through the SRD modules. If you are using a
modem, also test the modem communications.
To conduct these tests, you will need the
following:
•Two SRD modules and interfaces
•Two FOCUS chassis
•Two assigned time slots on the FOCUS
DS1 line for channels A and B
RS-232 (Female)
Pin2–RD
Pin3–TD
Pin 5 – Signal Ground
Pin 7 – RTS
Pin 8 – CTS
Pin1*
Figure 22–8 SRD Interface DB-9 Pin out.
* For +5V on Pin 1, R3, R4, R5 & R6 must be 0 Ω.
Figure 22–7. SRD Status Indicators.
STATUS LED
INJECT/EJECT
LEVER
COMPONENT SIDE
SOLDER SIDE
CHANNEL C
DS0
DS0
CHANNEL D
TX
RX
CHANNEL B
CHANNEL A