Operating system name and version - CentOS Linux 7 (Core)
Version of smsd - 3.1.5
package repository - Installed by yum install smstools
Name and model of a modem - Huawei GSM moem - 1436
Interface: USB

Hi Team ,

I had so many issues on configuring SMStools with Nagios core. But finally able to fix most of the issues thanks for the SMSTools3 community. But now i'm getting the below issue.

When sms are sending from the Nagios sometimes i'm getting the below error.

2018-03-21 09:52:44,6, GSM1: Signal Strength Indicator: (22,99) -69 dBm (Excellent), Bit E rror Rate: not known or not detectable
2018-03-21 09:52:44,6, GSM1: Selecting PDU mode
2018-03-21 09:52:45,7, GSM1: -> AT+CMGF=0
2018-03-21 09:52:45,7, GSM1: Command is sent, waiting for the answer
2018-03-21 09:52:45,7, GSM1: <- OK
2018-03-21 09:52:45,7, GSM1: -> AT+CMGS=60
2018-03-21 09:52:45,7, GSM1: Command is sent, waiting for the answer
2018-03-21 09:52:45,7, GSM1: <- >
2018-03-21 09:52:46,7, GSM1: -> 0011000A9170767404440000FF3550E714146416A5D42908296D25A7A0 F41C548582AE6532A81996836431102CA7ABC974331C6805ABCD6020192C8603
2018-03-21 09:52:46,7, GSM1: Command is sent, waiting for the answer
2018-03-21 09:53:46,7, GSM1: put_command expected (OK)|(ERROR), timeout occurred. 1.
2018-03-21 09:53:46,7, GSM1: <-
2018-03-21 09:53:46,3, GSM1: The modem answer was not OK:
2018-03-21 09:53:46,5, GSM1: Waiting 10 sec. before retrying
2018-03-21 09:53:56,6, GSM1: Checking if modem is ready
2018-03-21 09:53:56,7, GSM1: -> AT
2018-03-21 09:53:56,3, GSM1: write_to_modem: error 5: Input/output error
2018-03-21 09:54:06,7, GSM1: ->
2018-03-21 09:54:06,3, GSM1: write_to_modem: error 5: Input/output error
2018-03-21 09:54:17,7, GSM1: -> AT
2018-03-21 09:54:17,3, GSM1: write_to_modem: error 5: Input/output error
2018-03-21 09:54:27,7, GSM1: ->
2018-03-21 09:54:27,3, GSM1: write_to_modem: error 5: Input/output error
2018-03-21 09:54:37,7, GSM1: -> AT


But after some times with 1-5 min delay modem get start and sent the sms to the destinations. Is any one knows the issue behind this.

This is the smsd.conf file as i configured.

devices = GSM1
logfile = /var/log/smsd/smsd.log
loglevel = 7
# 3.1.5 introduced smart logging
# once your configuration is OK, set log level lower (5 is good in most cases)
smart_logging = yes
infofile = /run/smsd/smsd.working
pidfile = /run/smsd/smsd.pid

[GSM1]
device = /dev/ttyUSB2
incoming = no
check_network = no
#pin = 1111


Thank you.