8
3.4.2
Multiple Host
The multiple host configuration allows more than one host multiplexer
to be connected to the multidrop line. This requires a Modem Sharing
Unit. The SRX Host multiplexers are connected to the MSU ports
using the “Modem to Composite” cable. The MSU is connected to the
Modem or DSU/CSU using the male to female RS-232 cable. The
modem or DSU/CSU should be set for constant carrier operation (RTS
forced ON). For information regarding host computer port connections,
see Section 6.
DCB
DSU/CSU 56
INSDCDRTSCTSTxDRxD
SELF
TEST
DIGITAL
L O O P
LOCAL
L O O P
REMOTE
TEST
SELECT
O P T I O N
MODEM READY
LINE ERROR
ACTIVITY
POWER
NEXT
INCR OK!
SRX 8/16 MULTIPLEXER
DC B
OPTION
MODEM READY
LINE ERROR
ACTIVITY
POWER
NEXT
INCR OK!
SRX 8/16 MULTIPLEXER
DCB
BPV
CARRIER LOSS
FRAME ERROR
SYNC LOSS
POWER
NEXT
INCROK!
T-DRIVER
D
C
B
RESET
Host
SRX
SRX
Modem/DSU
See Section 6
Modem to Composite Cable
Ribbon Cable
Modem
Sharing Unit
3.5
Installation Summary
1. Set the host modem or DSU/CSU for constant carrier operation.
(RTS forced ON)
2. Connect the host modem or DSU/CSU to the phone line. If this
is a multiple host installation, connect the Modem Sharing Unit
composite port to the modem or DSU/CSU.
3. Configure the host SRX multiplexer(s).
a. Map at least one port to each drop to be installed.
b. Configure the SRX ports for correct speed, parity and flow
control.
c. Connect the SRX to modem or DSU/CSU using the Modem to
Composite cable supplied. If this is a multiple host
installation, connect the SRXs to the Modem Sharing Unit.
d. Connect a properly configured CPU port to each mapped SRX
port. See Section 6 for host port cabling information.
4. Go to each remote site and follow the steps in Section 3.5 of the
SPL Multidrop manual.
