20
Description
T801-4 Installation and Operation Manual
© Tait Electronics Limited September 2007
PORT A - DALMAN
GPS
This 15-way female D-range provides the RS-485 interface between the
T801-4 and the Dalman external GPS receiver. This port provides
connections for the following signals:
■
a regulated 12VDC output limited to 1.1A
■
a 1PPS signal input at standard TTL levels
■
a 1PPS RS-485 data pair input at standard RS-485 levels
■
a data link input (RS-485 data pair at standard RS-485 levels)
■
a data link output (RS485 data pair at standard RS-485 levels).
This port is generally referred to as “
PORT A
” in the rest of this manual. The
pin allocations for this port are described in detail in the following table.
f
Pin
Signal Name
Signal
Type
Logic
Notes
1
+12VDC
power
output
power supply for Dalman external GPS
receiver
2
RXD+ EXTNL A
input
RS-485 NMEA data input
3
RXD– EXTNL A
4
1PPS+ EXTNL A
input
1PPS RS-485 input
5
1PPS– EXTNL A
6
1PPS VALID IN
input
active low (<0.8V) = 1PPS
valid
alternative input connection for VALID
signal (from QS
2
RSU);
internal 10k
Ω
pull-up resistor to 3.3V;
maximum input voltage = 9V
7
not connected
8
1PPS TTL IN
input
5V TTL
maximum input voltage = 9V
9
not connected
10
TXD+ EXTNL A
output
RS-485 data output
(not used)
11
TXD– EXTNL A
12
GND
ground
13
not connected
14
not connected
15
not connected
external view
J
B
C
D
E
F
G
H
I
1)
1!
1@
1#
1$
1%
