L3 Technologies AISD1 Manual Do Utilizador

Marine Systems

Aviation Recorders

Page 3–7

Initial Issue

165M0601-00
Feb. 01/05

The “A”, “B” and “C” leads are as defined in IEC 61162–1, 61162–2 and V.11.

“A” and “B” are both signal leads with “C” being the effective return for both the “A”
and “B” leads.

“A” and “B” operate differentially to each other.

High–level output voltage is 4V minimum from the “A” lead to the “C” lead and from
the “B” lead to the “C” lead.  Low–level output voltage is 0.4V maximum.

Recommended maximum output current capability is 110mA.

Input is differential from “A” to “B”.  Effective input resistance is 4.9k ohm across “A”
and “B” and 96k from “A” or “B” to “C”.

Differential input voltage threshold is 250mV maximum.

Inputs will meet the requirement of withstanding +/–15V between any two leads, “A”,
“B” or “C”.

Each transponder will come shipped with an 100 inches long IEC data cable (P/N
024M0599-00) terminated at one end by a J4 connector. (Refer to NO TAG,
Figure 4–3 and Figure 3–2.) The IEC data cable is shielded and contains three
smaller diameter cables, each of which is also shielded. Each of these smaller
cables contains three shielded twisted pairs (STP) each and each STP includes a
drain wire. A low speed unidirectional (input only) data channel (4800 Kbs) is carried
through one STP, and a high speed bidirectional (input/output) data channel (38400
Kbs) will require two pairs.

A terminal block is the preferred installation method for completing the data interface
(NMEA) because data output from a ship sensor ( dGPS, ROT, Gyro) may not sub-
scribe to a standard pinout definition.   As such, each installation may require that
the installer identify and cross reference the sensor pinouts with the IEC pinouts,
which is a well defined standard pinout description.  The terminal block allows for
greater flexibility in completing the connection to the ship’s sensors.