Interface specifications – Westermo DDW-142-485 User Manual
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6642-22511
Interface specifications
Power
Rated voltage
24 to 48 VDC
Operating voltage
19 to 60 VDC
Rated current
245 mA (405 mA) @ 24 VDC (with 500 mA USB load)
124 mA (200 mA) @ 48 VDC (with 500 mA USB load)
Rated frequency
DC
Inrush current, I²t
10.6 mA²s @ 24 VDC
24.7 mA²s @ 36 VDC
42.4 mA²s @ 48 VDC
Startup current*)
2 x Rated current
Polarity
Reverse polarity protected
Redundant power input
Yes
Isolation to
All other
Connection
Detachable screw terminal
Connector size
0.2 – 2.5 mm² (AWG 24 – 13)
Connect the unit using at least 18 AWG (0.75 mm²) wiring
Shielded cable
Not required
* External supply current capability for proper start-up.
RS-422/485
Electrical specification
EIA RS-422/485
Data rate
50 bit/s – 2 Mbit/s
Data format
7 or 8 data bits, Odd, even or none parity, 1 or 2 stop bits
(2 stop bits only when no parity is set).
Circuit type
TNV-1
Transmission range
Up to 1200 m / 0.74 mi, depending on data rate and cable
type
Isolation to
Power, I/O realay output, I/O Digital input, SHDSL line,
Ethernet
Connection
Detachable screw terminal
Connector size
0.2 – 2.5 mm² (AWG 24 – 12)
Shielded cable
Not required, but recommended in railway installations close
to the rails.*
Conductive housing
Yes
* To minimise the risk of interference, a shielded cable is recommended when the cable is located inside 3 m
boundary or the cable is longer than 30 m and inside 10 m boundary to the rails and connected to this port.