2070-6A Manual
4
2070-6Asm v2 Standard Manual A00886-A.doc
General Description
The 2070-6A Modem is a dual 1200
Baud FSK Modem for the 2070
Controller, which utilizes the latest
surface mount technology. The GDI
2070-6A meets or exceeds the
CALTRANS Transportation Electrical
Equipment Specifications (TEES) of
August 16, 2002 and applicable
addendum. This Modem plugs into the
A2 to A5 and A1 slots of the 2070
Controller and is held in place with two
thumbscrews. The front panel has two
M14 type connectors that are identical to
the C2S and C20S connectors on the 170
Controllers. Therefore, cables made for
the 300 series cabinets will work with the
2070-6A.
The 2070-6A also converts the EIA-485
signals for SP1-4 on the back plane of the
2070 to EIA-232. These signals are
available in the M14 (C2 and C20)
connectors on the front panel if the
Modem sections are not being used. A
front panel switch can turn off each
section of the Modem individually so that
it doesn’t interfere with the EIA-232
communication that might be going on.
The front panel of the 2070-6A also has
Full Duplex/Half Duplex switches for
each channel. A 5
th
switch powers down
the entire Module so that it can be
inserted or taken out while the power to
the 2070 is on. This prevents any of the
parts on the 2070-6B Modem or the 2070
Controller from being harmed during
insertion or being unplugged.
Six LEDs are also located on the front
panel, 3 for each channel. They include
Transmit Data (TX), Receive Data (RX),
and Carrier Detect (CD).
All of the RS-232 signals in the C2S and
C20S connectors are optically isolated
from the controller signals. The 5V
supply and Ground in the C2S and C20S
connectors are also isolated and
individually fused at 200ma with a solid
state PTC resettable to protect the 2070’s
internal power supply.
The 2070-6A Module is built with
surface mount parts for increased
reliability and to reduce the parts count.
The use of all surface mount parts has
allowed us to put all of the parts on a
single PC Board. The digital section and
first modem are on the top side of the
board. The second modem is on the back
of the PC Board. Power and Ground
planes prevent crosstalk and isolate the
two modems from each other
The GDI 2070-6A also has an anti-
streaming option that can be selected
with a dipswitch on the PC Board. Anti-
steaming will prevent a remote site from
monopolizing the communication path in
a multi-drop configuration. Anti-
streaming is not normally used on the
Master end.
Separate switches also allow the timings
on the handshake and modem control
signals to be cut in half for faster
communications.
Specifications
Each section of the Modem is identical
and therefore these specifications apply
both Modems.
Physical….220mm x 177mm x 40.44mm.
Temp………..-37 to +74 degrees C.
