Iem 2455 modbus rmap not in pro3

[ClaudioNastasi]

Hi all,

I'm having trouble getting two Schneider Electric IEM2455 meters to communicate over Modbus RTU.

Setup

18 x PM5100 meters communicating correctly on the same network

2 x IEM2455 meters not communicating

Modbus RTU (2-wire RS485)

Baud rate: 19200

Parity: None

Meter addresses: 2 and 3

Wired directly to the meter for testing using Modscan32

Connected to terminals:

10 = +

11 = -

Symptoms

Modscan32 returns 0 responses / "Received invalid response to Modbus query"

No data can be read from the meters

The PM5100s work fine with the same Modbus settings

The IEM2455 display shows valid electrical measurements and no obvious faults

No "P Fail" indication

Communication LEDs (A/B) show little or no activity

Sometimes when Modscan polls, TX flashes and occasionally both TX/RX flash together, but still no response is received

At other times there is absolutely no LED activity

Additional Observation

Yesterday I could see an "RMAP" menu/item on the IEM2455 display, but today it is no longer visible. I'm not sure whether this is related to the communication issue or just a menu/access-level setting.

What I've Checked

Meter powered correctly

Address and baud rate verified

Direct connection to meter (not through gateway)

2-wire RS485 connection

Tried polling with Modscan32

Other Modbus devices on site communicate normally

Questions

Has anyone experienced an IEM2455 that appears healthy but will not respond to Modbus?

Is there a setting that enables/disables Modbus communications on the IEM2455?

Does the disappearance of the RMAP menu indicate a configuration issue or firmware problem?

Are there any known issues with IEM2455 firmware affecting Modbus RTU communications?

Any suggestions would be appreciated.

Thanks.

[Jesus_Diaz · Accepted solution]

Hello @ClaudioNastasi,

Could you please check which register map you have selected in the meter? Refer to page 16 of the user guide, as the offset may not be correct depending on the selected register map. Which registers are you trying to read?

Also, when connecting the iEM2455 directly, which serial configuration are you using? Please share a screenshot. Have you tried adding a 120-ohm resistor, as suggested in the user guide?

Lastly, please try reversing connections 10 and 11 and check again.

Thanks,

JD

[rohith-s]

Hello @ClaudioNastasi ,

In addition to JD's feedback, try to read one parameter at a time.

Example: Refer to the below register map details

Try reading one register at a time.

Regards,

Rohith S

L4 - Technical Expert