Connecting Modbus SL power meters to PAS800

[lasalm1989]

Hi,

I have a requirement to increase the number of Modbus SL power meters to PAS800. Since PAS800 only support 32 Modbus SL devices, I'm planning to connect the power meters to PAS800 using PAS600 . I can't increase to network ports available in the upstream network.

Please recommend my design is correct or not, please recommend any other options available.

Please find system specifications below
Power meter : METSEPM2220
Polling interval : 15mins

Baud rate : 19200

Upstream network bandwidth : 300Mbbs

Please recommend how many PAS600 can be connected to 1 PAS800

[Guillaume_Evrard]

hello @lasalm1989 ,

What do you want to do with your PAS800, only modbus tcp gateway ?

PAS can accept only 128 modbus tcp devices, devices connected to PAS600 (Child gateway) will be modbus tcp devices. You will have to play with the virtual IDs if you want to match the IDs.

Kind Regards 

[lasalm1989]

Hello Guillaume,

Thank you for your explanation. I would like to humbly clarify my requirement:

• The PAS600 is intended to connect additional Modbus SL power meters (METSEPM2220) to the PAS800, helping to overcome the 32-device limit while also reducing the number of Ethernet ports needed on the upstream switch.

• The PAS800 is mainly used to log the data locally, so that in the event of an upstream network failure, no measurement data is lost.

• Since the number of upstream switch ports is limited, my main concern is understanding how many METSEPM2220 meters can be practically connected to one PAS800 through PAS600 units, given the polling interval (15 minutes), baud rate (19200), and upstream bandwidth (300 Mbps).

I would be grateful if you could kindly confirm whether this design is appropriate and advise on the recommended number of PAS600 units that can be connected to one PAS800.

[Guillaume_Evrard]

hello,

128 +32, regarding data sampling you need to see if you are below the PAS800 limit, for modbus serial link you need to make the computation taking into account baudrate, number and type of registers, number and time of devices and time it takes to return the modbus com. Pay attention that PAS800 will check communication with the device every 15s by polling it and in case of 15 min sampling, PAS will poll all the registers every minute.

Kind Regards