907 multiplexer

This topic has 9 replies, 7 voices, and was last updated 14 years, 1 month ago by T-Boy.

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October 16, 2010 at 12:50 pm #3897

Adam Freeburn
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Can anyone easily explain why i cannot get anything to work through this fibre 907 multiplexer, i have 2 x 485 channels, only one of which i can get to work which is used for ROV telem. i have a sonar that works fine on the bench in rs232 and rs 485 but i cannot get it to work through the multplexer, i also have a conan manip which we would also like to have running through the 907 but for the moment i would just be happy to get a sonar picture. There are no twp so cannot use them.

i have a an antique workclass rov called a dolphin

October 16, 2010 at 3:06 pm #29491

alan child
Participant

Mate,
I cut and past this from the manual on line at http://www.moog.com/products/multiplexers

The 907 video / data multiplexer provides digital transmission over 1 or 2 singlemode or multimode optical fibers for 3 high quality video channels and 6 bidirectional data channels (4 x RS-232 and 2 x RS-485 / 422 / TTL) in a single, compact PC / 104 form factor card.
Expansion cards may be added to convert data channels on the motherboard to other data formats, such as Ethernet, analog sonar, hydrophone and Tritech ARCNET, or to replace each motherboard channel with up to 8 lower data rate serial channels. Optical power budgets are typical 20-26 dB with 2-4 km of multimode fiber or 10 km of singlemode fiber. LEDs provide on-board diagnostics for data, video and optical link status.

only last line i think of interest, ie LEDs on the board to fault diagnose or BITE purposes

may be of help
Al404

October 17, 2010 at 5:21 am #29492

Jeremy
Participant

Check the following:
Dip switch settings for baud rate, your twisted wire might be inverted on the plugs, broken fibre, power to the boards.
That should give you a good start.

October 17, 2010 at 5:52 am #29493

Adam Freeburn
Participant

rs 485 works fine on the telemtry string, but not for the sonar, i am now checking dip switches for baud rate manipulation. Pictures and telemtry are fine so i beleive fibre is in good condition.

i have also tried changing seaprince over to rs 232, and works fine on the bench, but cannot get it to work through the 907.

Regards

Adam

October 17, 2010 at 9:00 am #29494

rov_er
Participant

Hi Adam,

I assume the fibre is ok as you can get the telemetry string work properly.

It could be a problem in the 485 channel, have you tried to send the sonar on the channel that worked fine for telemetry?

Check if your mux is compatible with the fibre (SM or MM)…if not, you can have problems when sending multiple channels in the fibre.

Double check your 485/232 connections and baud rates.

Last but not least, connect a led to the 485/232 connections (RX and TX for 232) at the receiving end, to see if you get the string…if so, the problem is likely to be elsewhere than the mux.

October 17, 2010 at 12:50 pm #29495

luckyjim37
Participant

If the fibre is ok and telemetry on one channel is good can you run the telemetry up the spare 485 channel?

Also does the Sonar have a termination resistor fitted top and bottom if needed this may be the cause of the Sonar not talking. Although that is from memory and may only be needed if multiple tritech sensors are used.

October 17, 2010 at 5:18 pm #29496

rov_er
Participant

Also does the Sonar have a termination resistor fitted top and bottom if needed this may be the cause of the Sonar not talking.

Termination resistors on SCU and subsea head are needed when using ARCNET as telemetry interface, and in general should be removed when using RS485 (refer to your system manual to check this).

October 18, 2010 at 12:04 pm #29497

Adam Freeburn
Participant

Thanks for your help guys, we got it going today, ended up i should have changed two dip switches on SW3, and yesterday i only changed one. Sonar is now running fine, cannot get it to work through any of the RS232 channels but we are happy with it the way it is for the time being.

Thanks again.

Now what do you know about a didson??

November 17, 2010 at 4:43 am #29498

Amilcar Lopez
Participant

Thanks for your help guys, we got it going today, ended up i should have changed two dip switches on SW3, and yesterday i only changed one. Sonar is now running fine, cannot get it to work through any of the RS232 channels but we are happy with it the way it is for the time being.

Thanks again.

Now what do you know about a didson??

What do you need to know?
I have been working with Didson 3 years now.
Is magnificent when you have zero viz.
It runs through Ethernet, it’s relatively easy to interface, once you have it working is just straight forwards and almost never fails.
If you need any help just sent a PM

November 17, 2010 at 7:46 am #29499

T-Boy
Participant

Didson – Yes, I’ve worked with this chappie before.

Post Katrina salvage ops.

We had zero, and I mean you couldn’t see your manip in front of your P & T no vis, and once you got your head round interpreting the screen (Takes about 5 minutes) it’s great.

I wonder how it compares though to say the Blueview system?
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