Specifications

Reference Guide
6-5
Interface Card Interface Card Descriptions
The pins shown in JP1 are used to wrap the wires from an externally provided clocking source.
A standard wire-wrap tool is used to make the connection. The pins shown in JP2 are used to
wrap the wires from a second external clocking source.
The Ext-1 (JP1) pins are labeled “Sh” (Shield Ground), “T1” (Tip1) and “R1” (Ring1) and the
Ext-2 (JP2) pins are labeled “Sh” (Shield Ground), “T2” (Tip2) and “R2” (Ring2).
The RJ48 connection labeled P1 is used to connect the external timing to the external sync port
on the Interface Card with a short module plug to plug cable. (This cable is provided with the
system.) External clock sources are shown on the Interface card as
ext1
and
ext2
under
Primary Clock and Secondary Clock.
Note:
Refer to correction grounding procedures of external timing sources.
6.2.1.5 Equipment Grounding Requirements
When connecting cables from other AC-powered equipment (such as computer terminals) to
the Interface card,
make sure the other equipment is properly grounded
. Ground
connections are normally provided by the ground (third) prong of an AC plug. Some PCs,
especially portables and laptops, have power supplies with two-pronged plugs; they are not
properly grounded.
When a cable is run from a PC that is not properly grounded to the Interface port of the
system, a high voltage differential (up to 100 VAC) may result between the system and
the PC. This can severely damage the Interface card, PC, or both.
As a rule, all cards with data interface connectors (RS-232, RS-422, RS-530,etc.) could be
damaged if connected to poorly grounded equipment.
All persons authorized to use or
service the integrated access system should be familiar with good grounding practices.