Of all the legacy Schneider DIN rail meters, the only one that has half hour profile, is the PM3255.
We can now read totals, profile, event and phasor graphs from this meter, over Modbus TCP or Modbus RTU. Although the protocol is still limited in terms of how fast you can read the profile, we have managed to alter the protocol a small bit to download 10 profile periods per transaction instead of 1, which is manageable if you do remote reads via a GPRS modem. The transaction turnaround time via GPRS is much longer than locally over a TCP/IP or RS485 network. This means you do not need a (Schneider) server on site to read the profile (very fast) 1 record at a time. Even if all the meters are installed on a large RS485 network, if you can set the profile period to a half hour, you can read them relatively fast, since you are reading 10 records at a time.
The profile needs to be enabled via the meter's local UI (the LCD screen has buttons on the side you use to program the meter). If you set the profile period to 30 minutes, you'd have about a month of data. If you leave it on 15 minutes, you'd have only one half of a month. Select option 3, which profiles the Active Energy total (importing) and the Q1 Reactive Energy total.
If you have another Schneider meter, e.g. the PM3250 or PM3200, that does not support profile, we suggest you add it as a generic Modbus Meter, just reading the real time Energy Total.

Transcribed from support call
Do you need to buy the Modbus TCP to Modbus RTU converter?

PNPSCADA can work with or without a Modbus TCP to Modbus RTU converter. It is configurable when you add the meter in PNPSCADA.

Transcribed from support call
So how would I talk to a Schneider meter if I don't have the R5000 Modbus TCP to Modbus RTU converter

The Schneider meter talks Modbus on RS485 (that is called Modbus RTU)
You would connect a modem or etherpad directly onto the RS485 network. As long as the modem/etherpad talks the same baudrate as the meter (it is configurable - make it 9600 baud); PNPSCADA can read the meter directly through the modem/etherpad.

Transcribed from support call
So why would it ever be a good idea to buy the Modbus TCP to Modbus RTU device? Since costs money

Modbus is a Master->Slave protocol, on RS485, which means that there can be only 1 master. If there is another process at the site, e.g. another BMS (Building Management System) at the site that already communicates to the meters, there will be interference with corresponding data corruption on the RS485 medium.
The Modbus TCP gateway allows for multiple Masters to potentially talk to the same RS485 network and meters, without interfering with each other (as long as there is enough time available in total for both to do all their communication).
However, to use Modbus TCP, PNPSCADA would have to be able to access the static IP address of the Modbus TCP to Modbus RTU gateway. The most common way that that is possible, is when you have a local PNPSCADA server on site, and it accesses the gateway over the LAN.

Just an observation in case anyone is thinking of profiling in the conventional (ie half-hourly) sense with the PM3255:

As I understand the user manual (see link below), the PM3255 supports only a basic form of profiling which Schneider call 'energy logging'. To quote from the user manual :

'The 3 log types are: 

• Day: the log interval is 1 day. The logging occurs at 8:03 A.M. every day and the accumulated active energy for the previous 24 hours is logged.
• Week: the log interval is 1 week. The logging occurs at 8:03 A.M. every Sunday and the accumulated active energy for the previous week is logged.
• Month: the log interval is 1 month. The logging occurs at 8:03 A.M. on the first day of each month and the accumulated active energy for the previous month is logged.'
  

It seems that the PM3255 simltaneously logs daily, weekly and monthly energy deltas, with the 3 log length being : past 45 days, past 30 weeks and past 13 months respectively.

User manual for PM3255 is here (see page 24).

Actually, the Schneider PM3255 CAN be used for half hour logging of profile. 

 It is called the Power Demand Logs, and you can specify a period of 1 to 60 minutes. Only the PM3255 has that feature, not the other PM3200 meters.

The profile is in the so called 'Power Demand Logs' as referenced below:

For non 3255 meters, e.g. 3155, use the Generic Modbus meter option, and read register 3204 (x4) for the Total Active Energy import, as below.

for the 3155

Some Schneider meters (I have a Schneider 3155 like this) may also use 'Modbus Register Address=3205' and 'Modbus Register Format=4 Byte Integer (big endian)' for them to work (even though register 3205 was not in the documentation we received from Schneider). Also I had to set the Multiplier to 1/1, as the meter was returning kWh values and as such no multiplication was necessary.

If you are having trouble communicating to multi-dropped meters, you might need to connect an earth to the comms module of each meter. If you touch the comms cables and the comms lights go crazy (next to the comms cable), then this is definitely the problem.

default password is 0010

PM3255 and IEM3255 are essentially the same meter.