Operating system name and version: Linux mint 15???
Version of smsd: no idea
Smsd installed from: package repository
Name and model of a modem / phone: ericsson hs2350
Interface: USB / ttyACM0 or 1


Hi
if I connect using cu -l /dev/ttyACM0
I can enter commands and it looks like it works

e.g. I entered AT+CPMS? and then AT+CPMS="SM","SM","ME" and it responds OK each time.
e.g.
AT+CPMS?
+CPMS: "SM",0,30,"SM",0,30,"ME",1,30

OK


But in the smstools logs all I get is this repeated ad infinitum:
2016-11-01 10:00:48,3, GSM1: write_to_modem: error 5: Input/output error
2016-11-01 10:00:58,3, GSM1: write_to_modem: error 5: Input/output error
2016-11-01 10:01:08,3, GSM1: Error: Unexpected answer from Modem after +CREG?, waiting 1 sec. before retrying

Since I can use cu, there shouldn't be an IO error?
I quit CU then restarted smstools, no change. (invoke-rc.d smstools restart)
Even if smstools is running cu works on the same port.....

smsd.conf, modem config part:
[GSM1]
init = AT+CPMS="SM","SM","ME"
device = /dev/ttyACM0
incoming = yes
sending_disabled = yes
rtscts = no (I tried yes and no difference)
baudrate = 19200
#baudrate = 115200
communication_delay = 5

NB cu works when forced to 19200 baud so I am pretty sure i got it right.


Any ideas???

I turned on debug mode this is the log:

There is a repeating section then the section below
It is receiving commands as I thought, but it says
"modem not registered"

I figure it is sending CREG=2
but the modemd doesn't respond with CREG? => 5

***************REPEAT START
2016-11-02 05:38:42,7, GSM1: -> AT+CSQ
2016-11-02 05:38:42,7, GSM1: Command is sent, waiting for the answer
2016-11-02 05:38:43,7, GSM1: <- +CSQ: 99,99 OK
2016-11-02 05:38:43,5, GSM1: Signal Strength Indicator: not present of not measurable, Bit Error Rate: not known or not detectable
2016-11-02 05:38:43,7, GSM1: -> AT+CREG?
2016-11-02 05:38:43,7, GSM1: Command is sent, waiting for the answer
2016-11-02 05:38:44,7, GSM1: <- +CREG: 2,0 OK
2016-11-02 05:38:44,5, GSM1: MODEM IS NOT REGISTERED, WAITING 1 SEC. BEFORE RETRYING 100. TIME
**************REPEAT END
2016-11-02 05:38:45,3, GSM1: Error: Modem is not registered to the network
2016-11-02 05:38:55,6, GSM1: Checking device for incoming SMS
2016-11-02 05:38:55,6, GSM1: Checking if modem is ready
2016-11-02 05:38:55,7, GSM1: -> AT
2016-11-02 05:38:55,7, GSM1: Command is sent, waiting for the answer
2016-11-02 05:38:55,7, GSM1: <- OK
2016-11-02 05:38:55,6, GSM1: Pre-initializing modem
2016-11-02 05:38:56,7, GSM1: -> ATE0+CMEE=1;+CREG=2
2016-11-02 05:38:56,7, GSM1: Command is sent, waiting for the answer
2016-11-02 05:38:56,7, GSM1: <- OK
2016-11-02 05:38:56,6, GSM1: Initializing modem
2016-11-02 05:38:57,7, GSM1: -> AT+CPMS="SM","SM","ME"
2016-11-02 05:38:57,7, GSM1: Command is sent, waiting for the answer
2016-11-02 05:38:57,7, GSM1: <- +CPMS: 0,30,0,30,1,30 OK
2016-11-02 05:38:58,7, GSM1: -> AT+CSQ
2016-11-02 05:38:58,7, GSM1: Command is sent, waiting for the answer
2016-11-02 05:38:58,7, GSM1: <- +CSQ: 99,99 OK
2016-11-02 05:38:58,6, GSM1: Signal Strength Indicator: not present of not measurable, Bit Error Rate: not known or not detectable
2016-11-02 05:38:58,6, GSM1: Checking if Modem is registered to the network
2016-11-02 05:38:59,7, GSM1: -> AT+CREG?
2016-11-02 05:38:59,7, GSM1: Command is sent, waiting for the answer
2016-11-02 05:38:59,7, GSM1: <- +CREG: 2,0 OK
2016-11-02 05:38:59,5, GSM1: MODEM IS NOT REGISTERED, WAITING 1 SEC. BEFORE RETRYING 1. TIME

May be rfkill related

I enabled mobile broadband and it seems to be working (I haven't tried sending or receiving an SMS yet)

So I tried to undo it but it still reports it is registered with the network

So I used
rfkill block wwan
and it reports it can't register again with the network again.

rfkill unblock wwan
and it automatically connects.... modem is registered to the network

When wwan is unblocked and modem can register, is the signal quality reported properly? If it's not, you can disable the feature using the setting status_signal_quality = no.

How did you get rid of that Input/output error?