Using Datalogging module to communicate with Micro Motion 2700 transmitter

[rb6783]

I'm trying to use the Datalogging and Supervisory Control Module to communication with the Micro Motion 2700 transmitter over ModBus and am having no luck getting a response from the transmitter.  I've use the ProLink software to set up my communcation parameters and have made sure that my RS485 port is working, but I still get no response from the transmitter.  I've attached my ModBus.lvproj that I've modeled after the ModBus Fundamentals example.  This is my first time using this module, or trying to communicate over ModBus, and I feel like there's something big that I'm missing.  So if anyone can give me some help I'd appreciate it.

Also, if someone has accomplished this and would like to share their .vis I'd be eternally grateful!

Thanks!

[ajcrico]

Hi,

Good morning!

i would like to ask a few questions regarding your concern.

1.  What is the complete model number of your transmitter?

2. Do you have the serial number?

3. What converter are you using? 

4. Are you connected to terminals 7 and 8 of the transmitter? Red on 7, black on 8?

5. Did you select service port as the protocol with the correct COM number?

6.  What error message did you get when you tried connecting to the transmitter with Prolink?

For us to assist you better, please send us an email at flow.support@emerson.com or you may contact us at 1-800-522-6277.

Hope to hear from you soon!

Regards,

Alexander John Rico

[rb6783]

Good morning,

In response to your questions:

1.  The model is 2700.

2.  The full SN is 2700R12ABAEZCZ.

3.  I am using the StarTech USB to RS-485 serial adapter cable.

4-6.  I do not receive any error message when I connect to the ProLink software through this adapter and COM 5.  During the ProLink software training the 2700 transmitter had to be rewired to work with this adapter cable.  

I think that I am not mapping the address correctly to get the flow rate output.  I just get zeros.  The attached .vi is trying to read the volume flow units holding register at 40042 and the volume flow rate scaled integer at address 30005.  

Thanks for you response and any further help you can give!