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iSerial Read Data Error

Posted: Sat Sep 22, 2012 2:36 am
by vdoshi
I'm trying to read my 2 Omnimeter II UL v.3 via iSerial and when I use EKM Dash, I get a "Read Regular Data Error" for each meter.
I have changed the IP of the iSerial device and am able to access it from the PC. I have changed the UART baud rate to 9600. I have connected Terminal A from the meter to Terminal T+ on the iSerial and Terminal B on the meter to Terminal T- on the iSerial. I have set the meter number as the S/N number from each meter. On the meter, both connections are on the left hand side connector (terminals 3 & 2 respectively). I also do not get any blinking on the ACT LED on the iSerial.
I have tried connectin to the iSerial device via serial (local) and via TCP/IP (remote), but both give the same result.
I tried the VCOM software to detect the iSerial device, but it cannon find a device...however, I am able to reach it via the browser.
The problem is that I cannot tell whether the iSerial is receiving data from the meters or the PC is not able to connect to the iSerial.

Any help or suggestions are welcome.

Re: iSerial Read Data Error

Posted: Sat Sep 22, 2012 2:41 am
by vdoshi
As per the instructions I'm supposed to connect RS485 terminal A+ on the meter to terminal T+ on the iSerial and RS485 terminal B- on the meter to terminal T- on the iSerial. However, I can only see terminals A & B for RS485 on the meter. I'm not sure where the + & - are comming from. Have I connected the meter correctly?

Re: iSerial Read Data Error

Posted: Mon Sep 24, 2012 1:40 pm
by Seth
A and A+, as well as B and B- are interchangeable.


Re: iSerial Read Data Error

Posted: Mon Sep 24, 2012 3:28 pm
by Jameson
It sounds like you are really close.

It also sounds like the iSerial is seeing your meter read requests (the ACT light is flashing which indicates RS-485 traffic). This is a good start.

2 things to check first:

What meter number are you using? Are you using the EKM-Omnimeter number that is laser marked right below the LCD screen? Will you please email us a screenshot of your meter setup screen?

Have you changed any of the other UART serial settings in the iSerial? Will you send us a screenshot of this as well?

It sounds like you have the RS-485 date wires properly connected. You can email us a digital photo of how the communication wires enter the iSerial and how they enter the 2 Omnimeters so we can look it over for you.

Best regards,

Re: iSerial Read Data Error

Posted: Tue Sep 25, 2012 6:35 am
by vdoshi
Thanks for the reply.
First of all, the ACT lights are NOT flashing, so I'm assuming I have a problem there. I will send you images of the wiring and screenshots of the software setup shortly.

Re: iSerial Read Data Error

Posted: Tue Sep 25, 2012 7:21 am
by vdoshi
Please find attached the screenshots of the UART Setup screen, the EKM Meter setup and the EKM Dash. I will post the images of the physical wiring as soon as possible.


Termination ?

Posted: Tue Sep 25, 2012 2:50 pm
by Nevland
you might try terminating the 485 terminals at the meter. Mine will not work without the termination.
I have definitely determined this. Someday I might get a chance to investigate this further.
Those little screws on the meter make it hard to experiment however.

Needs DC path A to B ?? Unterminated voltage to high ?? Just some of my guesses. Transmission line was only 3ft
(1 meter) long during my testing, doubt that it had refection problems.


Re: iSerial Read Data Error

Posted: Tue Sep 25, 2012 3:33 pm
by Jameson
Thanks for your input Bill, it is very much appreciated. Would love to get some dialogs going on the forum.


I am not seeing a glaring issue in the setup of the EKM Dash or the iSerial that you have sent. It is set to once a minute which will make the setup a little harder.

I would try setting the Dash to read your meters "As fast as possible" for a while. This will read your meters once a second. The ACT light on the iSerial should flash once a second (once for every read). Let us know if the ACT light does not flash.

The settings that you show in your iSerial look good. Besides changing the IP address in the iSerial, are there any other changes that you made? Is it still set to be a server?

I will be interested to see the photos of how the RS485 data wire is connected.


Re: iSerial Read Data Error

Posted: Wed Sep 26, 2012 2:24 am
by vdoshi
Hi Guys,
Thanks for your comments. I'll try terminating all the meters are the iSerial device and I'll try increasing the meter reading to "as fast as possible". In the mean time, attached are some pictures of my physical connection.
Just a note, the distance between the iSerial device and the first meter is approximately 12 meters. Would that cause a problem?

Re: iSerial Read Data Error

Posted: Wed Sep 26, 2012 1:19 pm
by Jameson
Hello Vishal,

From the photos you have posted, it looks like you have the meters and the iSerial connected correctly (assuming you have good contact between the terminal blocks and the twisted-pair wire.) To make sure you have a good connection, it is best to back out the terminal block all the way, then insert your bare wire, then tighten the terminal block screw back down.

We would still like to know if the ACT light is flashing on the iSerial. If it is not flashing the problem is before the iSerial. If it is flashing once a second (once per read) and your meters are not being read, then the problem is after the iSerial on the RS485 side.