IDP-782 - Hardware Guide
Cable Selection
Cable length should be as short as possible and built to the following guidelines:
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For reliable operation, use twisted pair and shielded cables for data connections to the terminal.
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18-22 AWG is recommended for proper crimping into the mating connector.
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Transmitting can consume up to 2 A peak current, therefore use a 2.5 A Slow Blow fuse, regardless
of the voltage.
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Minimum recommended wire gauge is 22 AWG for cable lengths up to
25 meters and 20 AWG for cable lengths up to 40 m.
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If the power cable length exceeds 4.57 m (15 ft), the input voltage range should be derated by 1 volt
for every 46 cm (1.5 ft) increase in length. Make sure the derated input voltage meets the terminal
minimum input specification of 9 V.
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Ensure that the cable operating temperature matches the terminals operational environment.
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If exposed to sunlight, ensure the cable jacket is UV stabilized.
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Cable should have operating voltages exceeding 100 V.
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Provide a separate return ground reference connection for cable lengths longer than 2 m if using
analog inputs. With 2 m cable lengths and a single ground return connection, analog voltage
readings errors introduced by ground reference difference in the return cable should be less than
0.2 V.
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Without a separate ground reference, the voltage drop induced across the ground reference affects
the accuracy of the analog reading. Changes to the current consumption that occur with changes to
the terminal's mode (cellular transmit, satellite transmit) change the analog input reading.
RF Immunity
If the terminal is intended for operation in a strong RF environment, it is recommended that cables used for
power, data interfaces and I/O be shielded and grounded. Data interface cables (RS-232, RS-485, and
CAN) must use twisted pairs wiring.
It is important to do field testing with RF environments before finalizing the cable design.
Tools
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Wire Cutter
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Wire Stripper
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Crimping Tool
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Fine-tip Soldering Iron
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Solder
For production cable assembly, SkyWave recommends the crimping and extraction tools listed in Table 10.
T213, Version 02
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