Prosoft MVI56E MNET/MCM Modbus Setup

Hi,

I'm having some issues getting my PLC to talk with a meter and genset controller over Modbus.

The PLC is a ControlLogix 5572 with 2 Prosoft cards - MVI56E MCM and MNET.

The meter is an Eaton PXM 2000.

The genset controller is an Onsite Energy MGC-2010.

I was kind of thrown to the wolves with this project as I don't have much Modbus experience other than the basics taught in school.

The meter and genset controller both have ethernet ports on them and are to be connected to a switch, and connected to the PLC through the EN2T card. This leads me to believe that the MNET card is to be configured as a client (master) to poll values from the devices and the MCM card is to act as a slave to feed values to SCADA.

I'm just having difficulties getting the devices to talk to the PLC. I'm only trying to talk to the meter at the moment, as it has less values I need to pull and I have more info about it. I've followed the instructions on Prosoft's website for setting up the card in the Configuration Builder, it all seems setup right to me. But I'm not reading any values from the meter at all right now, and the APP LED on the card flashes red occasionally which I believe signals communication errors.

Any ideas on which direction I should start in?

Thanks

Hello,

You're in luck because I am doing this exact thing at another site, except the generator is connected to the DCS rather than the PLC. You said that PLC has an EN2T which I suspect is connected to the SCADA system.

Ignoring the PLC cards for a moment, you first need to determine whether the devices are using Modbus serial or Modbus TCP. The PowerXpert and the generator controller can communicate with either Modbus Serial or TCP depending on what was specified. The generator would have been shipped with a TCP gateway if ModbusTCP was requested.

The following assumes you have imported both of the Prosoft AOIs.

Scenario 1 - PowerXpert and Generator via Modbus Serial:
The MCM card will be used to communicate to both devices. In this case, the MCM is the master, and the two devices are slaves. For this to happen, the jumper on the card needs to be set to match the settings of the device (i'm guessing RS-485). Configure MCM.Config.Port1 for this network (baud, parity etc). Next, you need to configure MCM.Config.Port1MasterCommand for every command you wish to send to the PowerXpert, and generator.
I can give more detail here later. Just a note that the IntAddress parameter refers to the MCM's internal database.


Scenario 2 - PowerXpert Modbus Serial, Generator ModbusTCP:
For serial, see scenario 1.
I suspect that the generator was supplied with ModbusTCP gateway which would explain the MCM and the MNET in one PLC rack.

Rather than "master/slave " the MNET card uses different terminology because it can have multiple "masters" or "slaves." Internal to the MNET card lives a database which we'll call the "server." Devices connected to the MNET card are "clients." The MNET card can request data from a client (a device such as the generator), or a client can request data from the MNET card (such as a SCADA system / RTU / DCS etc).

With that in mind, you need to configure Client commands in a conceptually similar way to the MCM, but with different software: Prosoft Configuration Builder.

You'll also need to know the IP addresses that you'll assign to the MNET card port, and the Generator (or SCADA).

Please reply once you have figured out the actual device network.

Get yourself a copy of the "Simply Modbus" TCP client here:

http://www.simplymodbus.ca/TCPclient.htm

Use it to talk to your PXM 2000, and MGC-2010, and MNET card individually (I'm not sure why you included a MVI56E-MCM since the MNET does the same thing as the MNET with the exception of not supporting serial Modbus connections).

Once you get each device talking to the SM client (using the SM client to send out a request, and then observing the response), then it's a pretty sure thing that they will all talk together. If a device won't talk to your SM client, then it's not going to be ready for prime-time either. And it's pretty much a dead giveaway that the problem (of the moment) resides in that device.

Near the lower lefthand corner in the SM client, you will see two checkboxes for "High Byte" and "High Word" first. This sets your endian-ness. It should be Big-endian, but you never know.

Start with that and give us an update please.

Thanks for the replies.

@rootboy

Thanks for that, I'll give that a try at site tomorrow and keep you posted. I'm getting the feeling that there's something not quite right with the devices right now but I'll find out for sure tomorrow.

@MrAnonEMoose

Yes I'm almost positive it's scenario 2 that I'm dealing with here. I have the configuration built for the Prosoft card and downloaded to it, IP addresses are set on the card and the meter, both are on the same subnet. I'll try rootboy's suggestion tomorrow and see what I can come up with.

Thanks again, I'll update tomorrow.

Update

So I remembered I have MdBus on my PC, I tried reading registers on my PC from the MNET card and it worked just fine so I believe my configuration is correct. I'm still unable to pull any data from the PXM 2000 meter which leads me to believe it's not properly configured.

The meter needs to be configured by connecting to it with an ethernet cable and punching in its default IP into a web browser with Java enabled, just like setting up a wireless router I'm hoping. I'm going to try and play around with it some more and see what I can figure out. If anyone has any experience with these meters or anything similar, please feel free to post as I'll be checking back whenever I get stuck.

Thanks