LDM2485A and
LDM2485B
Signal Powered High Speed
RS-232 to RS-485 Converters
Dataforth鈥檚 Model LDM2485A & LDM2485B high speed, RS-232 to RS-
485 interface converters can turn your PC, terminal or other RS-232 device
into an RS-485 workstation. Operating over 2 to 4 wires, at data rates up to
115.2 kbps, Models LDM2485A & LDM2485B let your RS-232 machine talk
with up to 50 addressable devices in a multipoint polling environment. Since
multipoint environments can be difficult to work with, these products have
five separate configuration parameters (carrier control, RTS/CTS delay,
receive impedance, transmit-off impedance and echo) that allow you to fine
tune the converters to your particular application. And to keep your application
up and running, both models have built in surge protection. The Model
LDM2485A has a DB-25 connector for RS-232 environments, while the Model
LDM2485B has a DB-9 connector for EIA-574. Both models have several
options for twisted pair connection.
Features
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AVAILABLE WITH DB-25 (RS-232) OR
DB-9 (EIA-574) INTERFACE
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CONFORMS TO THE EIA RS-485 STANDARD
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OPERATES ASYNCHRONOUSLY, POINT-TO-
POINT OR MULTIPOINT, OVER 2 OR 4 WIRES
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UP TO 50 TERMINAL DROPS IN A MULTIPOINT
POLLING ENVIRONMENT
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DATA RATES TO 115,200 BPS
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RANGE UP TO 9.0 MI (14.5 KM)
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DATA PLUS ONE CONTROL SIGNAL PASSED IN
Specifications
Model
Transmission Format
Data Rate Range
Data Rate bps
Distance
km
mi
4.2
LDM2485A/LDM2485B
Asynchronous
0-115.2K bps
115.2K
2.6
4.7
38.4K
2.9
7.4
9.6K
4.6
14.5
1.2K
9.0
EACH DIRECTION
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SELECTABLE RTS-CTS DELAY
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ABLE TO OPERATE WITH OR WITHOUT 鈥淓CHO鈥?/div>
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CARRIER MAY BE CONTINUOUS OR
RS-232/EIA-574 Interface DB-25/DB-9
RS-485 Interface Options
Transmit Line
Transmit Mode
Control Signals
RJ-11 or RJ-45 jack or terminal block
with strain relief
2, 4 wire unconditioned twisted pair
4-wire, full or half duplex; 2-wire half duplex
DSR turns 鈥淥N鈥?immediately after the
terminal raises DTR; DCD turns 鈥淥N鈥?after
recognizing the receive signal from the line;
CTS turns 鈥淥N鈥?after the terminal raises RTS.
0 or 8 msec
The carrier is switch selected either
continuous operation or controlled by RTS
600W power dissipation at 1 ms
Draws operating power from the RS-232 or
EIA-574 data and control signals; no AC
power or batteries required.
32擄 to 122擄 F (0擄 to 50擄 C)
2.66" x 2.10" x 0.73" (68 x 53 x 19 mm)
2.50" x 1.20" x 0.75" (64 x 31 x 19 mm)
2 oz (57 gm)/1.4 oz (40 gm)
鈥淐ONTROLLED BY RTS鈥?/div>
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NO AC POWER OR BATTERIES REQUIRED
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600 WATTS OF SILICON AVALANCHE DIODE
SURGE PROTECTION 鈥揝TANDARD
Dataforth does not authorize or warrant its products for use in life support/critical applications.
Ordering Information
LDM2485A-P
LDM2485A-S
LDM2485A-PJ1
LDM2485A-SJ1
LDM2485A-PJ4
LDM2485A-SJ4
LDM2485A-P25S
LDM2485A-S25S
LDM2485B-P
LDM2485B-S
LDM2485B-PJ1
LDM2485B-SJ1
LDM2485B-PJ4
LDM2485B-SJ4
Male DB-25 w/terminal block
Female DB-25 w/terminal block
Male DB-25 w/RJ-11 jack
Female DB-25 w/RJ-11 jack
Male DB-25 w/RJ-45 jack
Female DB-25 w/RJ-45 jack
Male DB-25 w/female DB-25
Female DB-25 w/female DB-25
Male DB-9 w/terminal block
Female DB-9 w/ terminal block
Male DB-9 w/RJ-11 jack
Female DB-9 w/RJ-11 jack
Male DB-9 w/RJ-45 jack
Female DB-9 w/RJ-45 jack
廬
RTS/CTS delay
Carrier
Surge Protection
Power
Temperature
Size: 2485A
Size: 2485B
Weight
26
1
