What are the limitations of using PM8000 as a Modbus gateway

[Yarom]

Hello,

I know that we can use the PM8240 (any PM8000) as  Modbus RTU to TCP gateway.  The question is are there limitations? Cases that we should not use it so?

We have a TAPCON device for an MV Transformer that communicates through RS485. We thought of putting a PAS600 gateway. We have in the same panel a PM8240 so thought perhaps to use the gateway feature.

Any information would be appreciated.

Yarom

[Mehran_Mehrnia]

Hi @Yarom 

As mentioned in PM8000 user guide:
There are two types of Ethernet gateways that you can configure on your meter:
• EtherGate: A single TCP connection communicates through the gateway meter to a serial network of devices.
• Modbus gateway: Up to a maximum of 32 Modbus client TCP connections communicate through the gateway meter to a serial network of Modbus devices.

Best Regards,

-Mehran

L3 Expert Advanced metering

[Yarom]

Hi Mehran,

Yes. This part I know about. That is one of the purposes we are thinking of using the PM8240 installed. What I am asking is if there is some limitation as to using the PM8000 as a gateway? Are there a limited number of registers that can be used? Would using it as a gateway affect the TCP/IP network?

Are there any communication limitations that would get us to consider the PAS600 as a proper gateway?

Best regards,

Yarom

[Mehran_Mehrnia · Accepted solution]

Hi @Yarom 

So, in brief, PAS600 is exclusively designed for communication applications and Gateway functionality. However, ION meters such as PM8000 are mainly designed for metering and energy management applications, where communication capabilities are additional features considered as low priority, especially when the meter is busy with metering tasks such as power quality, waveform, and high-speed data recording.

When PM8000 is configured as a Gateway, it does not affect the TCP/IP network, and there should not be any limited number of registers, as it forwards the message to the serial devices or forwards the response back to the Modbus client, provided that the meter is not busy. Otherwise, it could affect response time, or in the worst case, the communication gets dropped if the meter's CPU is fully loaded.

Best Regards,

-Mehran

L3 Expert Advanced metering

[Yarom]

Thank you for that! That was what I was looking for and wanted to make sure.

Best regards.

[dan2071]

Could you tell me if it is possible to read the values of a PM8000 once it has been setup as a Modbus Master? I can see all RTU slaves through the PM8000 but not the actual PM8000.

I so, could you advise on how to add this into EBO.

Thanks, Dan

[Mehran_Mehrnia]

Hi @dan2071 

No matter whether the PM8000 is set up as a Modbus Master or Modbus Gateway, it can be polled by any Modbus client tool to provide the requested data by setting the slave ID of the PM8000 meter to 255 and using a Modbus access right of 'Read/Write' or 'Read Only.'

This forum is dedicated to Metering & Power Quality. To get assistance on EBO and how to add the device and registers, please post your question in EcoStruxure Building Operation Forum.

Best Regards,

-Mehran

L3 Expert Advanced metering