Geometrics.com
Geometrics Knowledgebase

Knowledgebase Home | Glossary | Favorites | Contact | Login Knowledgebase Home | Glossary | Favorites | Contact | Login
Search the Knowledgebase Browse by Category
OhmMapper Troubleshooting Guide
Article Details

Last Updated
2nd of July, 2009

“No Data Received” message on G-858 Survey Screen

The “No Data Received” message means you don't have data coming into the console.  This could mean one of two things 1) the receiver cannot see the transmitter signal, or  2) the console cannot see the data coming out of the receiver.  In other words:

1.  You really don't have data because the receiver cannot detect the transmitter - or -

2.  The data communication link between the receiver and the console is broken.

You first need to figure out which it is. 

A.  If the blue light on the receiver is not flashing and you get messages like the following on the OhmMapper Test screen:

Phase A, Phase B

Setting Gain

then the receiver is not detecting the transmitter.  There are several possible reasons for this.

a. You are over an area that is too conductive to use the Tx/Rx separation you are using.  If that is the case the problem will go away when you use a shorter rope.

b.  You are over a buried pipeline, along side a railroad track, next to a reinforced sewer line, along side a grounded metal fence, or any other long linear metal structure close to your survey line.

c.  The transmitter is turned off because of a low battery or because it is broken.  If the blue light on the transmitter is flashing its three-flash sequence (such as short-long-short or long-short-short, etc.) then the transmitter is probably working.  You should use you battery load test that comes with the OhmMapper to test the batteries.

B.  If the blue light is flashing on the receiver, and you do not see anything updating on the OhmMapper test screen then you have a loss of communication between the receiver and the console.  The possible culprits, from the most likely to the least likely, are:

a.  Bad dipole cable from the pointy end of the receiver to the optical wand.  Swap this with a spare cable to see if the problem goes away.

b.  Bad dipole cable (tow cable in this case) from the RCVR end of the optical wand to the console cable.  Swap this to see if the problem goes away.

c.  Bad optical wand.  Swap this with your spare.

d.  Bad console cable. Swap this with your spare.

e.  Bad RS232 electronics on the receiver board.  If this is the problem the unit would need to come back here.  It is more likely one of the cables is bad.

f.   Bad RS232 port on the OhmMapper console.  This is highly unlikely, but possible.  I have only seen one or two console com ports go bad in all the years we have been shipping OhmM

Visitor Comments
No visitor comments posted. Post a comment
Post Comment for "OhmMapper Troubleshooting Guide"
To post a comment for this article, simply complete the form below. Fields marked with an asterisk are required.
   Your Name:
   Email Address:
* Your Comment:
* Enter the code below:
 
Related Articles
No related articles were found.
Attachments
No attachments were found.

P: (408) 954-0522   ·   F: (408) 954-0902   ·   E: sales@mail.geometrics.com   ·   2190 Fortune Drive   ·   San Jose, CA 95131 U.S.A.