Operating system name and version: Linux RHEL 6
Version of smsd: 3.1.14
Smsd installed from: sources
Name and model of a modem / phone: Maestro 100 GSM/GPRS Modem, High Speed GPRS
Interface: serial


I am only trying to recieve messages currently, but I have noticed sometime the messages are not recieved correctly.
I get the following in the spooled file.

Error: Cannot decode PDU, see text part for details. From: Received: 11-06-09 10:45:53 Subject: GSM1 Modem: GSM1 IMSI: 234108733152144 Report: no Alphabet: ISO Length: 535 PDU: name,1,57.4,0.12,50.1 Pos: ^^~here(1) First tried with PDU mode new (with CSA): PDU ERROR: Position 1,2: While reading first octet: invalid character(s) in string Next tried with PDU mode old (without CSA): PDU ERROR: Position 1,2: While reading First octet of the SMS-DELIVER PDU: invalid character(s) in string No success. This PDU cannot be decoded. There is something wrong. If you are unsure, confused or angry, please view the GSM 03.40 (ETSI TS 100 901) and related documents for details of correct PDU format. You can also get some help via the Support Website.

What is confusing it it appears the message is not in PDU format, as the field PDU: contains the actual text of the message. The length is also invalid.


Here is a the same message recieved correctly

From: xxxxxxxxxxxx From_TOA: 91 international, ISDN/telephone From_SMSC: 447802000332 Sent: 11-06-09 11:50:38 Received: 11-06-09 10:46:08 Subject: GSM1 Modem: GSM1 IMSI: 234108733152144 Report: no Alphabet: ISO Length: 44 PDU: 0791448720003023000C914497111111110000116090110583402CEE70BBCC8AB16A37178D0573C564AC1ACC1553D0D1E939283D078541F4F29C0E6A97E7F3F0B90C name,1,57.4,0.12,50.1 this is a test message

I am not sure if the problem lies in the modem or smstools. Has anyone else had similar problems ?

thanks
Ben

I have not seen this kind of problem before.

Do you have a log with loglevel = 7, or smsd_trouble.log, which show whole communication with a modem when incorrect message was received?

I have just been playing witht he logging. I have set log_read_from_modem = yes in the conf file.

Looking at the data, it appears that the modem is sending out messages in non PDU format sometimes.

Clearly the invalid message is being read as a text message. Does smstools set the message mode before retrieving each message, just once, or rely on the default modem settings ?

Will turn up log level to 7 and see what happens.

Have been incontact with the modem suppliers and waiting to hear back from their technical support at the moment.

Message mode is set every time when receiving or sending is started after smsd has been idle. If more than one SMS is received consecutively, PDU mode is selected once, not for each message.

Ok here are two snippets of log at level 7, first one is ok, the second is a failure


2011-06-09 06:43:34,6, GSM1: Signal Strength Indicator: (19,0) -75 dBm (Good), Bit Error Rate: less than 0.2 % 2011-06-09 06:43:34,6, GSM1: Checking if Modem is registered to the network 2011-06-09 06:43:34,7, GSM1: -> AT+CREG? 2011-06-09 06:43:34,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:43:34,7, GSM1: <- +CREG: 1,1 OK 2011-06-09 06:43:34,6, GSM1: Modem is registered to the network 2011-06-09 06:43:34,6, GSM1: Selecting PDU mode 2011-06-09 06:43:35,7, GSM1: -> AT+CMGF=0 2011-06-09 06:43:35,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:43:35,7, GSM1: <- OK 2011-06-09 06:43:35,6, GSM1: Checking memory size 2011-06-09 06:43:35,7, GSM1: -> AT+CPMS? 2011-06-09 06:43:35,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:43:35,7, GSM1: <- +CPMS: "SM",3,50,"SM",3,50,"SM",3,50 OK 2011-06-09 06:43:35,6, GSM1: Used memory is 3 of 50 2011-06-09 06:43:35,6, GSM1: Trying to get stored message 1 2011-06-09 06:43:36,7, GSM1: -> AT+CMGR=1 2011-06-09 06:43:36,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:43:36,7, GSM1: <- +CMGR: 1,,58 0791448720003023000C914497171111110000116090218450402CEE70BBCC8AB16A37178D0573C564AC1ACC1553D0D1E939283D078541F4F29C0E6A97E7F3F0B90C OK 2011-06-09 06:43:36,5, GSM1: SMS received, From: 447971XXXXXX 2011-06-09 06:43:36,6, GSM1: Wrote an incoming message file: /darts/spool/sms/incoming/GSM1.9ZQmV7 2011-06-09 06:43:36,6, GSM1: Deleting message 1 2011-06-09 06:43:36,7, GSM1: -> AT+CMGD=1 2011-06-09 06:43:36,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:43:36,7, GSM1: <- OK

2011-06-09 06:44:18,6, GSM1: Signal Strength Indicator: (16,0) -81 dBm (Good), Bit Error Rate: less than 0.2 % 2011-06-09 06:44:18,6, GSM1: Checking if Modem is registered to the network 2011-06-09 06:44:18,7, GSM1: -> AT+CREG? 2011-06-09 06:44:18,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:44:19,7, GSM1: <- +CREG: 1,1 OK 2011-06-09 06:44:19,6, GSM1: Modem is registered to the network 2011-06-09 06:44:19,6, GSM1: Selecting PDU mode 2011-06-09 06:44:19,7, GSM1: -> AT+CMGF=0 2011-06-09 06:44:19,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:44:19,7, GSM1: <- ERROR +CMTI: "SM",3 2011-06-09 06:44:29,7, GSM1: -> AT+CMGF=0 2011-06-09 06:44:29,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:44:30,7, GSM1: <- OK 2011-06-09 06:44:30,6, GSM1: Checking memory size 2011-06-09 06:44:30,7, GSM1: -> AT+CPMS? 2011-06-09 06:44:30,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:44:30,7, GSM1: <- +CPMS: "SM",9,50,"SM",9,50,"SM",9,50 OK 2011-06-09 06:44:30,6, GSM1: Used memory is 9 of 50 2011-06-09 06:44:30,6, GSM1: Trying to get stored message 1 2011-06-09 06:44:30,7, GSM1: -> AT+CMGR=1 2011-06-09 06:44:30,7, GSM1: Command is sent, waiting for the answer 2011-06-09 06:44:31,7, GSM1: <- +CMGR: "REC READ","+447971XXXXXX",,"11/06/09,12:48:59+04" name,1,57.4,0.12,50.1 this is a test message OK 2011-06-09 06:44:31,5, GSM1: SMS received, From: 2011-06-09 06:44:31,6, GSM1: Wrote an incoming message file: /darts/spool/sms/incoming/GSM1.5IXVzo 2011-06-09 06:44:31,6, GSM1: Deleting message 1 2011-06-09 06:44:31,7, GSM1: -> AT+CMGD=1 2011-06-09 06:44:31,7, GSM1: Command is sent, waiting for the answer

smstools is setting the PDU mode, however where I am seeing failures the modem is replying
: <- ERROR +CMTI: "SM",3
to the first sending of -> AT+CMGF=0
No idea why.

The modem then resends -> AT+CMGF=0 after the error, but obviously something is wrong as the message is in plain text.
very strange

When PDU mode was set, the modem was receiving SMS at the same time. It seems that this caused the problem, but usually modems do not work like that. Because of error, smsd retried and got an answer OK. Still the mode is wrong, probably because the modem is receiving more messages.

You could try to save CMGF=0 to the modems profile. It seems that the modem defaults to ASCII mode, and does not remember the mode which was set through the AT interface.

Do you have a complete manual of AT commands for this device?

I have a datasheet from the supplier, it is a Wavecom AT command set. I assume internally it is a wavecom modem.

The +WSSW command for version number does comeback with a text string.

How would I go about setting CMGF=0 to the modems profile ?


suppliers pdf

Use the modem setting report_device_details = yes, restart smsd and show those details from the log.

2011-06-09 07:53:31,7, GSM1: ## Start of device details
2011-06-09 07:53:31,7, GSM1: # Manufacturer identification:
2011-06-09 07:53:31,7, GSM1: -> AT+CGMI
2011-06-09 07:53:32,7, GSM1: <- WAVECOM WIRELESS CPU
OK
2011-06-09 07:53:32,7, GSM1: # Model identification:
2011-06-09 07:53:32,7, GSM1: -> AT+CGMM
2011-06-09 07:53:32,7, GSM1: <- MULTIBAND 900E 1800
OK
2011-06-09 07:53:32,7, GSM1: # Revision identification:
2011-06-09 07:53:32,7, GSM1: -> AT+CGMR
2011-06-09 07:53:33,7, GSM1: <- R73_00gg.WMP100 2087432 121208 15:34
OK
2011-06-09 07:53:33,7, GSM1: # New message indications, list of supported modes:
2011-06-09 07:53:33,7, GSM1: -> AT+CNMI=?
2011-06-09 07:53:33,7, GSM1: <- +CNMI: (0-3),(0-3),(0-3),(0-2),(0,1)
OK
2011-06-09 07:53:33,7, GSM1: # New message indications, current settings:
2011-06-09 07:53:33,7, GSM1: -> AT+CNMI?
2011-06-09 07:53:34,7, GSM1: <- +CNMI: 0,1,0,0,0
OK
2011-06-09 07:53:34,7, GSM1: # Preferred message storage, list of supported mem's:
2011-06-09 07:53:34,7, GSM1: -> AT+CPMS=?
2011-06-09 07:53:34,7, GSM1: <- +CPMS: (("SM","ME","BM","SR"),("SM","ME"),("SM","ME"))
OK
2011-06-09 07:53:34,7, GSM1: # Phonebook storage, available mem's:
2011-06-09 07:53:34,7, GSM1: -> AT+CPBS=?
2011-06-09 07:53:35,7, GSM1: <- +CPBS: ("SM","FD","LD","MC","ON","ME","RC","MT","EN","SN")
OK
2011-06-09 07:53:35,7, GSM1: # List messages, list of supported stat's:
2011-06-09 07:53:35,7, GSM1: -> AT+CMGL=?
2011-06-09 07:53:35,7, GSM1: <- +CMGL: (0-4)
OK
2011-06-09 07:53:35,7, GSM1: # Delete message, list of supported values:
2011-06-09 07:53:35,7, GSM1: -> AT+CMGD=?
2011-06-09 07:53:36,7, GSM1: <- OK
2011-06-09 07:53:36,7, GSM1: # Phone activity status, list of supported stat's:
2011-06-09 07:53:36,7, GSM1: -> AT+CPAS=?
2011-06-09 07:53:36,7, GSM1: <- +CPAS: (0-5)
OK
2011-06-09 07:53:36,7, GSM1: # TE character set, list of supported charset's:
2011-06-09 07:53:36,7, GSM1: -> AT+CSCS=?
2011-06-09 07:53:37,7, GSM1: <- +CSCS: ("GSM","PCCP437","CUSTOM","HEX")
OK
2011-06-09 07:53:37,7, GSM1: # TE character set, current setting:
2011-06-09 07:53:37,7, GSM1: -> AT+CSCS?
2011-06-09 07:53:37,7, GSM1: <- +CSCS: "PCCP437"
OK
2011-06-09 07:53:37,7, GSM1: ## End of device details

Stop the smsd if it's running.

Reset the modem (power off-on).

Start smsd in communication mode:
smsd -C GSM1

Follow the instructions on screen.

Set "echo on" (for easier typing):
ATE1

Check the current mode:
AT+CMGF?

What was it?

Set it to PDU mode:
AT+CMGF=0

Store settings:
AT&W

Exit with Ctrl-C and reset the modem again. Once again start communication mode, and check the current mode. It should be 0.

Hopefully this will help, but let's see...

Ok I had actually done the AT&W already and on power up the modem is in PDU mode.

It appears that maybe sending any command and getting an error because the phone is recieving as message causes the text message to be in text mode. I have just seen this happen. I had just recieved a good message, so the modem was in PDU mode. This time trying to read a message when a new message arrives caused an error. It looks like pretty bad firmware in the modem.


2011-06-09 15:45:00,6, GSM1: Checking memory size
2011-06-09 15:45:01,7, GSM1: -> AT+CPMS?
2011-06-09 15:45:01,7, GSM1: Command is sent, waiting for the answer
2011-06-09 15:45:01,7, GSM1: <- +CPMS: "SM",1,50,"SM",1,50,"SM",1,50 OK
2011-06-09 15:45:01,6, GSM1: Used memory is 1 of 50
2011-06-09 15:45:01,6, GSM1: Trying to get stored message 1
2011-06-09 15:45:01,7, GSM1: -> AT+CMGR=1
2011-06-09 15:45:01,7, GSM1: Command is sent, waiting for the answer
2011-06-09 15:45:01,7, GSM1: <- ERROR +CMTI: "SM",2
2011-06-09 15:45:01,6, GSM1: Trying to get stored message 2
2011-06-09 15:45:02,7, GSM1: -> AT+CMGR=2
2011-06-09 15:45:02,7, GSM1: Command is sent, waiting for the answer
2011-06-09 15:45:02,7, GSM1: <- +CMGR: "REC READ","+000000000000",,"11/06/09,15:44:44+04" name,1,57.4,0.12,50.1 this is a test message OK

This was followed by 2 further bad messages, before again recieving 6 good messages

You could try a modem setting init = AT+CNMI=0,0,0,0,0. With these settings SMS deliver indications are not routed. But I do not believe that this helps, as 2011-06-09 06:44:30 there was no error but still modem used wrong mode.

Hopefully you will get a new firmware, or replacement device from the supplier.

So far I have seen 2 diffrerent messages ( AT+CMGF=0 and AT_CMGR=1) cause errors because a message is being recieved, which seem to cause the message mode to go back to plain text. I will try turning off the SMS deliever indications and see what happens tomorrow.


I am sending the logs and the problems I have to the modem distributor and they are going to talk with the modem people.

Ok a quick update.
This morning I have disabled the message notification as you have suggested and so far I have not seen any errors.
Of course as this seems to be down to timing, I may just be lucky. I have sent 5 burts of 10 messages without any errors, where before I would have had several.

Many thanks for your help

You have sent messages? I think the problem occurs when the modem receives messages.

Probably you are not asking for status report when sending messages. Before making a final decision with this modem, you could try to ask reports. In the SMS file use the header Report: yes, and in the configuration of modem add the settings:
primary_memory = SM
secondary_memory = SR

You could also use a global setting report = /var/spool/sms/report to save reports into different directory than normal messages.

Send some 10 messages and especially check how status reports are received and what are the message id numbers.

Sorry you misunderstand. I am sending the GSM modem the messages from my phone. I have a small android app to send multiple messages.
I have not actually sent any messages yet through smstools and the GSM modem.

I sent a string of 20 messages to the modem from my phone, with 16 arriving about 1 second apart with no errors. That just wasn't happening before. Disabling the SMS message notification, certainly seems to have made things better. I won't say it has fixed the issue until the modem people can find the reason for the errors and provide a fix or tell me yes, disabling SMS notification messages will stop it from happening.

Okay .

If you are going to use this modem for sending later, you could test it now with status reports. This is because some modems based on Wavecom chip have serious problems while receiving reports. If your device has problems, it's better to know it now when you already have contacted the supplier.