NorthStar Navigation 978/897-6600 Marine GPS System User Manual


 
SECTION SIX: Interfacing the 958 system
958 Installation Manual, Rev. A1 Page 29
Using 200 ppnm output
The 958 provides an open-collector transistor output (on pin 14) thats programmed to produce 200
pulses per nautical mile. The emitter of the NPN transistor is connected to ground, and its collector
connects to the output pin (see Figure 16: Wiring for 200 PPNM output, below). The output can
sink 100mA, and can withstand a maximum positive voltage of 50 volts.If the output connects to an
inductive device (for example, a relay), a spike suppression diode such as a 1N4001 should be
connected across the load. Cathode connects to the power side of the device and anode connects to
the output pin side. The output is normally open, switching to ground for 80ms. It supports speeds
from zero to 100 knots (clamps at 100kt).
Figure 16: Wiring for 200 PPNM output
Configuring the RS-232 port
The RS-232 port on the NMEA connector is used to interface to any any compatible SC104 output or
a PC for downloading waypoints or for uploading 958 software updates. The following sections
describe the RS-232 ports settings for SC-104 in, and copy port 1 and 2.
Using SC-104 in
THE SC-104 IN setting lets the 958 accept optional differential corrections from any source that
transmits the standard SC-104 data stream. When using SC-104 IN, be sure that the BAUD RATE
setting also matches the beacon receivers baud rate requirements.
Using copy port 1 and copy port 2
The COPY PORT setting lets you interface the 958 to many PCs without using an RS422-to-RS232
converter. Many PC application programs can be used for waypoint/route loading, chart programs,
data logging, etc. This function copies the output of the specified port 1 or port 2 data format
(NMEA 0183 or Raytheon 0183) to the RS-232 ports output for direct connection to the computer.
1. Press STAR to display the OPTIONS/SERVICE INFO screen, then press PORT
SETUP OPTIONS.
2. Press PORT 1 SETUP or PORT 2 SETUP to confirm that the port you want to copy
is now set to output the desired data format. If necessary, make changes now by