Chapter 3
Communication Ports
RUGGEDCOM RX1100P
Installation Guide
30
Connecting Multiple RS485 Devices
3. Insert the SIM card with the angled side first. An audible click will indicate the SIM card is in position.
4. Install the access panel.
5. Connect power to the device.
Supported Frequency Bands
WARNING!
Electromagnet radiation hazard – risk of serious injury. Do not exceed the maximum antenna gain.
Aside from causing cellular interference for other devices that use the same band, adverse health
effects for individuals in the area may occur.
Frequency Range
Band
Tx (MHz)
VSWR
Rx (MHz)
VSWR
Maximum
Allowable
Gain (dBi)
GSM 850
824-849
<2.5:1
869-894
<3.5:1
5
EGSM 900
880-915
<2.5:1
925-960
<3.5:1
5
GSM 1800
1710-1785
<2.5:1
1805-1880
<3.5:1
4
GSM 1900
1850-1910
<2.5:1
1930-1990
<2.5:1
4
Section 3.11
Connecting Multiple RS485 Devices
Each RS485 port can communicate with multiple RS485 devices by wiring devices together in sequence over a
single twisted pair with transmit and receive signals on the same two wires (half duplex). For reliable, continuous
communication, adhere to the following guidelines:
• To minimize the effects of ambient electrical noise, use shielded cabling.
• The correct polarity must be observed throughout a single sequence or ring.
• The number of devices wired should not exceed 32, and total distance should be less than 1219 m (4000 ft) at
100 kbps.
• The Common terminals should be connected to the common wire inside the shield.
• The shield should be connected to earth ground at a single point to avoid loop currents.
• The twisted pair should be terminated at each end of the chain.
The following shows the recommended RS485 wiring.
