There are 7 Satec 130 mfm meters looped to each other through rs-485 in series and end of the looping is connected to rs 485 to modbus tcp ip convertor (satec etc plus one ). We have to pull data in modbus tcp ip from  RTU .

Thus, we have single IP address ex ( 192.168.1.5 ) and multiple slave id eg , 8,9,10,11,12,13 .

The configuration in SDM is similar to that , normally all the mfm meters data reports . The issue is as soon as any one of the mfm meter is turned off or slave id of any one mfm meter is changed , all the remaining mfm meter reading starts fluctuating ie ( connecting – disconnecting ) continuously . but meters reports properly on modscan .

Steps taken :

• Tried to changed modbus parameters like polling delay , retries , response timeout etc .
• Reconfigured the pre again and all the signals
• Upgraded MBCIIO filmare version from 5.40 to 6.20

The problem still exists .

What is SDM?

What is the Modbus client that is creating the polls and getting the data?

What reason do you have to "change the slave ID of an mfm meter" once the network is established and running?

What exactly happens when one meter is turned off?

Do downstream meters fail to reply?  Do all meters fail to reply?  What else happens?
What action restores communication?

danw

What is SDM?

- SICAM DEVICE MANAGER ( Tool to configure A8000 RTU )

What is the Modbus client that is creating the polls and getting the data?

- RTU ( A8000 CP8050 processor ) 

What reason do you have to "change the slave ID of an mfm meter" once the network is established and running?

- the issue was raised when one of the mfm meter was turned off , once mfm meter was again turned on , all data were reports and all mfm meters got connected ... The behaviour was similar when we change slave id of any one device .. Since turning meter on and off was not feasible , so we tried to monitor behavior by changing slave id 

What exactly happens when one meter is turned off?

All the remaining meters data starts flactuating , ie they keep connecting and disconnecting on (visible on Sicam web  ) 

Do downstream meters fail to reply?  Do all meters fail to reply?  What else happens?
What action restores communication?

No , their connection is stable on MODSCAN and PAS software throughout , even when one meter is turned off , its on our RTU its starts connecting and disconnecting .

communication restores as soon as one meter is turned on again ( which was off ) , or slave id is restored to pervious value ( as per configuration )