User Manual

Marine Systems
Aviation Recorders
Rev. 06
Mar . 16/11
165M0014-10
Page 3--8
The IEC I/O electrical characteristics are as follows:
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.
Differentia l input voltage threshold is 250mV maximum.
Inputs will meet the requirement of withstanding +/--15V between any two leads, A,
BorC.
3.1.2.2 Data Cable
Each transponder will come shipped with a 100in--long IEC data cable (P/N
024M0088-00) terminated at one end by a J4 connector. (Refer to Figure 3 --3, Fig-
ure 3--3, and Figure 3--4.) The cable may either have a white covering (ECS cable),
or a grey covering (Alpha cable), and it is important to recongnize the wire color
changes between the two cables to insure a proper installation. No ma tter which of
thse IEC data cables is used, it 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 (4,800Kbs) is carried through one STP, and a
high speed bidirectional (input/output) data channel (38,400Kbs) will require two
pairs.
3.1.2.3 Terminal Block
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 p inouts, which
is a well defined standard pinout description. The terminal block allows for greater
flexibility in completing the connection to the ship’s sensors.
A junction box may be made available which terminates the data cable on the termi-
nal block and provides serial connectors to allow for easy connection to ship sen-
sors. However, the installer will need to confirm the pinout definitions for the sensor
outputs before completing the connection correctly.