Moog Components Group
201760 - RS-422/485 Daughterboard
2/24/2009
Page 7 of 9
RS-422/485 Data Activity LEDs
In normal operation with data traffic the following right angle bi-color LEDs, mounted on
the edge of the board (under the data connector) should be observed:
D32
Channel 1 lit RED for Tx, lit GREEN for Rx
D30
Channel 2 lit RED for Tx, lit GREEN for Rx
D26
Channel 3 lit RED for Tx, lit GREEN for Rx
D25
Channel 4 lit RED for Tx, lit GREEN for Rx
D22
Channel 5 lit RED for Tx, lit GREEN for Rx
D19
Channel 6 lit RED for Tx, lit GREEN for Rx
D17
Channel 7 lit RED for Tx, lit GREEN for Rx
D14
Channel 8 lit RED for Tx, lit GREEN for Rx
4
RS-422/485 Daughterboard Board Level Testing
i. If DC power +5V LED (D1) is out:
•
Make sure +5VDC is available at the motherboard connector J1.
•
Check 2Amp fuse (F1) with ohmmeter, replace with another fuse if blown
ii. If DC power 3.3 LED (D8) is out:
•
Problem with the 5V to 3.3V DC-DC converter circuit on the board. Not field
serviceable. Replace the board.
iii Faulty isolated power supply for channel pairs:
•
LED9 – Out Ch1&2 will not work
•
LED1 – Out Ch3&4 will not work
•
LED2 – Out Ch5&6 will not work
•
LED3 – Out Ch7&8 will not work
4.1.1 RS-422/485 Daughterboard Data Loop-Back Test
With a daughterboard in both the vehicle (ROV) and surface units, run RS-422 data into
pins 1 (+) and 5 (-) of the connector of channel 1 (as an example) being tested. The RS-422
data can be input into either the ROV or surface board. Connect the Rx to pins 2 and 6.. On
the other end of the link, short pins 1 and 2 (the positive signals) and pins 5 and 6 (the
negative signals) of the daughterboard channel 1 being tested. This process can be repeated
on every channel of the board. This will allow the two daughterboards to talk to each other
in loopback. Both RX and TX LEDs on both boards should be lit and/or flickering. If any
of the LEDs are not operating, check one of the other channels. If the LEDs operate on that
channel, replace daughterboard with a spare board or use the working channels only.
4.1.2 Test Data Channels
If an appropriate serial data test generator is available (or a PC with Communications
software, or even a square wave generator) the individual channels can be tested on a
