Specifications

Page 22–4
FOCUS System Manual
22.2.4 SRD-4, SRD-4N
This version has one RS-232 and one RS-485 on
each of two DS0s. Therefore the two DS0s in a
given DS0 are mapped to the same two end nodes.
The second DS0 may be mapped to the same or
different remote node. Sub-channels A & C are in
one DS0, as are sub-channels B & D. You must
use sub-channel A with either A or B at the remote
end. Similarly, you must use sub-channel C or D
with either C or D at the remote end. Sub-channels
A& B are RS-232 and sub-channels C & D are
RS-485. The SRD-4 is used for point-to-point
connections of either RS-232 or RS-485. The
SRD-4N has extra circuitry on the RS-485
interface that parallels and terminates the 2 RS-
485 sub-channels, allowing daisy-chaining
RS-485 LANs between nodes such as those used
to send DNP protocol between several sites. In
this application, the ‘D’ connectors are not used.
22.3 Installation
As with other FOCUS modules, we recommend
that you initially install and test the SRD modules
and interfaces in "test" chassis (i.e., chassis that
are not part of an operating network). This way,
you can quickly perform the acceptance test
without interfering with a live network. Whether
you are installing the modules in test chassis or
chassis that are on-line in a network, use the
installation procedure described here.
The SRD Module occupies one chassis slot. The
module's four channels require two (2) time slots.
It is important to remember that the SRD is a Data
Terminal Equipment (DTE) circuit. Refer to Table
22-2 for additional information.
Before installing the module and its interface,
make sure that:
• The FOCUS chassis is set up, energized,
and operational, with all necessary
common equipment [see Chapter 3
(Installation) of the instruction manual]
• The FOCUS Configuration Software (FCS)
has been installed on your computer [see
Chapter 3 (Installation, section 3.4) of the
instruction manual]
• Acceptance tests for the FOCUS chassis
and all previously installed equipment have
been done to rule out invalid test results for
this module
• FCS is up and running (see the online help
facility “FOCUS Configuration Software >
Starting FCS”)
22.3.1 Hardware Installation and
Connections
To install the SRD Module and interface,
complete the following steps.
1. Unlock the FOCUS chassis.
Execute the "Unlock Configuration"
command on the FCS Setup menu (see
"Unlocking the FOCUS Chassis" in the online
help for instructions). This puts the chassis in
a configurable state, allowing you to install
the SRD module and interface.
2. Insert the SRD Module into the FOCUS
chassis.
Carefully insert the SRD module into the top
and bottom grooves of any open slot on the
FOCUS chassis. Slide it all the way in until it
is well seated in the slot. Lock it into place
using the black ejector clip on the front of the
module.
When you first insert the SRD module, the
red/green status LED is red. If the module is
functional, the status LED turns green within
20 seconds. If the module is non-functional,
the status LED stays red, even after 20
seconds have elapsed.
3. Connect the SRD interface module to the
FOCUS chassis.
Attach the interface module to the rear of the
FOCUS chassis so that it connects to the SRD
module.
4. Connect the proper wiring/connector to the
SRD interface module.
Use a DB9 male connector to connect your
equipment to the interface. To properly wire