scadapack 330E and SR2MOD03

[farm]

I have been using the SR02MOD03 modem with ScadaPack RTUs in our clients, to make PPP GPRS connections  and have works well. Now, we have received some new modems to install in a client with several modems installed but the newer modems don’t work and they have the same code (SR02MOD03).

We maked some tests and with the older modem that we installed in 2014 works perfectly, if we install the newer bought in 2021 the connection fail and don’t get a IP.

Anyone had this problem? Any suggestions or documentation for this problem?

[ScottGuimond]

Hello farm,

Have you tried communicating with the modem through a simple terminal application to see whether the problem is on the modem side or the serial port side?

Using some AT commands you can verify if the modem has been registered with the cellular network:

(from page 51)

Examples of AT Commands
Some of the AT commands that can be sent to the modem once the communication is established
and verified are given here:
 AT+CGSN: The modem responds with a 15-digit number.
 AT+CPIN = xxxx: Enter the code of the SIM card xxxx (if active).
 AT+CSQ: Verify the GSM/UMTS/HSPA signal reception level.
 AT+CREG?: Verify the registration of the modem on the network

The above commands were pulled from the SR2MOD0X user manual:

User Manual 

If you verify that the problem is related to the serial port side, maybe you could provide the port configuration information that you are using in SCADAPack E configurator to see if there is anything of note.

One other note, looking through the manual I also noticed this statement that mentions one change from units manufactured before 1630 (2016 week 30):

(from page 7)

Document Scope
This manual describes how to install, configure, and use the SR2MOD02 and SR2MOD03 2G/3G
modems, based on descriptive information and how-to procedures. The modems are quad-Bands
(850/900/1800/1900 MHz) in 2G GSM Class 12/EDGE.
The modems with manufacturing dates greater than or equal to 1630 are six Bands (Band I
(2100 MHz), Band II (1900 MHz), Band IV (1700 MHz), Band V (850 MHz), Band VI (800 MHz)
and Band VIII (900 MHz)) in 3G UMTS/HSDPA/HSUPA.

[farm]

Hello Scott,

Thanks for the answer, the commands you suggested are simple commands to register on the modem's network, the problem happens at a later stage of the connection when we are already in PPP. Regarding the manual you provided it is outdated, because certain AT commands do not work. This situation is due to the change of the internal modem, the manual is made for a Sierra Wireless internal modem (page 67), and what we really have is a ublox modem.

Attached is a print of the serial port and PPP configuration.

[BevanWeiss]

You should be able to use the UBlox AT command reference

https://www.u-blox.com/sites/default/files/u-blox-CEL_ATCommands_UBX-13002752.pdf 

Then you can:

1. Identify the hardware / software versions of the ublox modem you have
2. From (a) work out which equivalent PPP / IP commands you should send to configure this modem
3. Test this out using your PC hooked up to the modem first
4. Test this out connected to a bench test RTU
5. Win

[farm]

Hello Bevan,

Thanks for the answer. I created a modem in windows 10 and windows xp to perform some tests. The conclusions were that with the old modem (sierra wireless) it works in both Windows 10 and XP, with the new modem (ublox) it doesn't work , I cheek during the handshake there is a problem and the connection fails, at RTU the same happens.

Best regards,

[BevanWeiss]

Which 'handshake'?
Are you using CHAP?

I'd say if you can't get it working with your PC, then no point trying it on the RTU.

You should be able to get diagnostics from the PC software which tells you which part of the connection attempt is failing.  That should let you zero in on the right settings to use.

[farm]

I, when performing the tests, analysed the windows diagnostic file, where it appears that when starting the PPP the modem cannot reach the understanding to open the connection. I don't know if it's due to lack of some configuration. But the configuration I have has already been validated by Schneider's own support. does anyone have any idea what it could be?

[BevanWeiss]

If the modem doesn't do what it's advertised to do, then you'd be best to return them to Schneider (after engaging with Tech Support for some kind of RMA).

Your local Schneider Tech Support would also be best positioned to ascertain whether your doing the right thing, and direct you if not.