3.4 CONFIGURATION SWITCH APPLICATIONS
The switch settings
generally
needed to configure the Model 2085
for various applications are shown in the table below.
Note:
Do not
change switch settings until you have
carefully
read
Section 3.3.
8
S1-1: “Xmt Off” Imp.
OFF
OFF
OFF
OFF
OFF
S1-2: “Xmt Off” Imp.
OFF
OFF
OFF
OFF
OFF
S1-3: RTS/CTS Delay
ON
ON
ON
OFF
ON
S1-4: Echo
OFF
OFF
OFF
OFF
OFF
S1-5: Carrier Control
OFF
ON
ON
Master-OFF
ON
Slaves-ON
S1-6: Rcv Impedance
ON
ON
ON
Master - ON
Slaves - OFF
Last Slave - ON
S1-7: 2-wire/4-wire
OFF
OFF
ON
OFF
ON
S1-8: 2-wire/4-wire
OFF
OFF
ON
OFF
ON
TYPICAL MODEL 2085 APPLICATIONS
Point-to-Point
Switch
Settings
Multi-point
4W
2W
4W
2W
4W HDX
4.0 INSTALLATION
Once you have properly set the configuration switches, you are
ready to connect the Model 2085 to your system. This section tells you
how to properly connect the Model 2085 to the RS-485 and RS-232
interfaces, and how to operate the Model 2085.
4.1 CONNECTION TO THE RS-485 INTERFACE
To function properly, the Model 2085
must
have one or two twisted
pairs of metallic wire. These pairs must be "dry" (unconditioned)
metallic wire, between 19 and 26 AWG (the higher number gauges may
limit distance somewhat).
For your convenience, the Model 2085 is available with several
different physical interfaces on the RS-485 side: DB-25 (following the
RS-520 standard), RJ-11 jack, RJ-45 jack, and terminal blocks with
strain relief.
4.1.1 4-WIRE CONNECTION USING THE DB-25
The DB-25 connector on the Model 2085's RS-485 side conforms to
the RS-530 interface standard. When connecting to an RS-485 device
that also conforms to the RS-530 standard, your cable should be
"crossed over" in the manner shown below:
MODEL 2085
RS-485 (530) DEVICE
SIGNAL
DB-25 PIN
DB-25 PIN
SIGNAL
XMT+
2 ...........................3
RCV+
XMT-
14 ...........................16
RCV-
RCV+
3 ...........................2
XMT+
RCV-
16 ...........................14
XMT-
NOTE: It is not necessary that the RS-485 device adhere to the RS-530
standard. However, you must make sure that the signals, polarities, and pairing
of your connection conform to the above diagram.
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