Raymarine ST40, Service Manual

Page: 21 / 70

Chapter 2, ST40 Depth Instrument
ST40 Instruments Service Manual 83149-2 2-9
EE2203822038
E22038
Chapter 2: ST40 Depth Instrument
Input/output signals
Connections to instrument
D4805-2
DEPTH_0V (Screen)
DEPTH+ (Blue)
DEPTH- (Black)
BATT+ (Red)
BATT- (Screen)
STALK (Yellow)
Raymarine
Limited
Signal Description
STALK Intermittent streams of (nominal) 12 V pulses
BATT- 0 V
BATT+ Nominal 12 V dc supply
DEPTH- Intermittent pulses at 200 kHz, approximately 400 µs wide, 300 V peak-to-peak
DEPTH+ Intermittent pulses at 200 kHz, approximately 400 µs wide, 300 V peak-to-peak
DEPTH_0V 0 V
Refer also to the ST40 Depth circuit diagram .
Self-test procedure
Each ST40 instrument has built-in self-test functions to aid fault diagnosis.
To self-test an ST40 Depth instrument:
• Press the and keys simultaneously for 4 seconds, to access self-test mode,
then within 2 seconds, press the and keys together momentarily, to start
self-test stage 1.
Self test stage 1
When entering self test stage 1, the instrument beeps and the display shows
TEST 1
,
for 1 second. The following tests are then performed automatically:
• SeaTalk self test, which checks the receive and transmit circuits.
• EEPROM test (read and write).
If the tests are satisfactory,
PASS
is shown on the display.