Specifications

Copyright © AMETEK
22
22. Sub-Rate Data (SRD-2/SRD-4/SRD-4N)
22.1 Description
Three versions of the SRD Module are currently
available. The SRD-2 Module provides two RS-
232 data circuits per DS0, and the SRD-4 Module
one RS-232 and one RS-485 circuit per DS0. The
SRD-4N includes extra circuitry to permit
extending RS-485 LANS between stations. All
versions support a total of four 0-9600 bps asyn-
chronous data channels over two DS0 channels.
The four circuits operate independently of each
other, simultaneously carrying their data/control
signals over two FOCUS DS0 channels, or time
slots.
The SRD module does not process the data
passing through it. Data and modem control
signals, such as those in Table 22-1, are trans-
ferred transparently across the FOCUS DS0
channels.
The Module's interface, consists of a DB25
Female connector that is fitted to the rear of the
chassis which electrically connects it to the SRD
Module. Three interfaces are available for the
SRD module, SRD-2, see Figure 22-1, SRD-4 &
SRD-4N, see Figure 22-3. The interface cables
have two or four DB9 Female connectors,
depending on which version module you have, for
directly connecting your RS-232 equipment, with
the SRD-2, SRD-4N and the SRD-4.
Figure 22–1. SRD-2 Interface Module.
J3
TX-C
TX-D
+
+
+
+
–
–
–
–
RX-C
RX-D
GND-C
GND-D
SRD
DB25
(Female)
RS-232
CIRCUIT A
RS-232
CIRCUIT C
14 RTS
15 RXDATA
16 TXDATA
17 +5V
18 GND
19 CTS
20 RTS
21 RXDATA
22 TXDATA
23 +5V
24 GND
25 SHIELD
CTS 1
RS-232
CIRCUIT B
RS-232
CIRCUIT D
DS01
CIRCUITS
A&C
DS02
CIRCUITS
B&D
RTS 2
RXDATA 3
TXDATA 4
+5V 5
GND 6
CTS 7
RTS 8
RXDATA 9
TXDATA 10
+5V 11
GND 12
CTS 13
(CIRCUIT A)
RS-232
DB-25 (Male)
Cable assy.
01W1-53C49-001
(A)
(B)
(C)
(D)
RS-232
DB-9 (Female)
RS-232
DB-9 (Female)
RS-232
DB-9 (Female)
RS-232
DB-9 (Female)
Figure 22–2. SRD-2 Interface Cable
DS01 – Circuits A & C
DS02 – Circuits B & D
Table 22–1. SRD Supported Control Signals.
Data & Modem Control Signals Supported
TX < Transmit Data
RX > Receive Data
RTS < Request to Send
CTS > Clear to Send