Westermo ODW-720-F1 - Manual (Page 12)

12 6651-2221
RS-232
Electrical specification EIA RS-232
Data rate 300 bit/s – 250 kbit/s
Protocol Asynchronous or synchronous
Data format 9 – 12 bits in asynchronous mode
Any type in synchronous mode
Data retiming Asynchronous mode only
Transmission range 15 m
Isolation to Status and Power port
Connection 9-pin D-sub female (DCE)
Shielded cable Not required, except when installed in railway applications as
signalling and telecommunications apparatus and located close
to rails*
Conductive housing Isolated to all other circuits and housings
* To minimise the risk of interference, a shielded cable is recommended when the cable is located inside 3 m
boundary to the rails and connected to this port.
The cable shield should be properly connected (360°) to an earthing point within 1 m from this port.
This earthing point should have a low impedance connection to the conductive enclosure of the apparatus
cabinet, or similar, where the unit is built-in. This conductive enclosure should be connected to the earthing
system of an installation and may be directly connected to the protective earth.