Product specifications

Hardware Description
5-14 80-99240-1 Rev. D
Grounding
The GSP-1620 modem has been designed to provide flexibility
in the area of grounding, with options to make connections
between digital ground and the OEM-provided chassis
ground (metallic enclosures). These grounding options are
also independently available for the DB-25 user interface,
Diagnostic port, and associated cable shields.
The GSP-1620 modem has been certified in accordance with
the technical and regulatory requirements of the FCC and the
European Union. The modem was tested in a configuration
that did not include, or require, an enclosure or specially
shielded cable configuration in order to demonstrate
compliance with the requirements.
OEM applications may need different grounding
configurations. The options are as follows:
• Option 1 — A chassis ground connection to the modem
may be established using conductive support posts/
screws between the modem mounting holes, where the
solder mask is exposed on both sides of the board, and the
OEM-provided chassis (metallic enclosure or base).
• Option 2 — DNI (do not install) resistors (R216 and
R217) on the modem circuit card allow for the option of
connecting digital ground and chassis ground together.
• Option 3 — The user interface DB-25 cable shield
termination is provided through Pin 1 of the DB-25
connector. The cable shield drain wire may be connected
to this pin to provide a termination of the cable shield to
either chassis or digital ground (options 1 & 2
dependency).
Caution
The RF connector ground is the same as the signal and power
ground. OEMs should understand this when designing an
integrated product for use in environments where surge protection
may be required. They should also be aware of this fact to avoid
ground loops in the final installation.