Westermo GDW-11 - Manual (Page 16)

16 6615-2203
Antenna
Frequency bands GSM900 TX 880 – 915 and RX 925 – 960 MHz
GSM1800 TX 1710 – 1785 and RX 1805 – 1880 MHz
Data rate CSD: up to 14.4 kbit/s, GPRS: up to 85.6 kbit/s
Connection SMA female, impedance: 50 ohm
Isolation to Power port 3 kV
rms
50 Hz 1 min
SIM
Electrical specification 3 volts SIM supported
Isolation to Power port 3 kV
rms
50 Hz 1 min
RS-422/485
Electrical specification EIA/TIA-485 ITU V.11
2-wire or 4-wire twisted pair
Data rate 1 200 bit/s – 115.2 kbit/s
Data format 7 or 8 data bits, Odd, even or none parity, 1 or 2 stop bits.
9-11 bit words
Protocol Transparent
Retiming Yes
Turn around time <10 ms (half duplex)
Transmission range ≤ 1200 m, depending on data rate and cable type (EIA RS-485)
Settings 120 Ω termination and failsafe biasing 680 Ω
Protection Installation Fault Tolerant (up to ±60 V)
Isolation to Power port 3 kV
rms
50 Hz 1 min
Connection Detachable screw terminal
Connector size 0.2 – 2.5 mm 2 (AWG 24 – 12)
Shielded cable Not required*
Miscellaneous Do not connect RS-232 and RS-422/485 simultaneously
* Railway installation close to the rails.
For a cable located inside 3 m boundary and connected to this port, the use of shielded cable is recommended,
this is to minimise the risk of interference. 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 con-
nected to the earthing system of an installation and may be directly connected to the protective earth.