diff --git a/openwisp-monitoring/files/monitoring.agent b/openwisp-monitoring/files/monitoring.agent
index 78457a8..d921c54 100755
--- a/openwisp-monitoring/files/monitoring.agent
+++ b/openwisp-monitoring/files/monitoring.agent
@@ -36,6 +36,41 @@ show_version() {
 
 echoerr() { echo "$@" 1>&2 && exit 1; }
 
+log() {
+	level="$1"
+	type="$2"
+	shift 2
+
+	if [ "$type" = "-v" ] && [ "$VERBOSE_MODE" -ne "1" ]; then
+		return 0
+	fi
+
+	case "$level" in
+		-i) level=daemon.info ;;
+		-w) level=daemon.warn ;;
+		-e) level=daemon.err ;;
+		-*)
+			echoerr "Invalid message level : $level"
+			;;
+	esac
+
+	logger -s "$@" -p "$level" -t openwisp-monitoring
+}
+
+time_to_seconds() {
+	time=$1
+
+	{ [ "$time" -ge 1 ] 2>/dev/null && seconds="$time"; } \
+		|| { [ "${time%s}" -ge 1 ] 2>/dev/null && seconds="${time%s}"; } \
+		|| { [ "${time%m}" -ge 1 ] 2>/dev/null && seconds=$((${time%m} * 60)); } \
+		|| { [ "${time%h}" -ge 1 ] 2>/dev/null && seconds=$((${time%h} * 3600)); } \
+		|| { [ "${time%d}" -ge 1 ] 2>/dev/null && seconds=$((${time%d} * 86400)); }
+
+	echo "$seconds"
+	unset seconds
+	unset time
+}
+
 check_available_memory() {
 	while true; do
 		total=$(ubus call system info | jsonfilter -e '@.memory.total')
@@ -52,9 +87,7 @@ check_available_memory() {
 			if [ -f "$file" ]; then
 				rm "$file"
 			else
-				[ "$VERBOSE_MODE" -eq "1" ] \
-					&& logger -s "Not enough memory available, skipping collect data." \
-						-p daemon.warn
+				log -w -n "Not enough memory available, skipping collect data."
 				return 1
 			fi
 		fi
@@ -63,14 +96,11 @@ check_available_memory() {
 
 collect_data() {
 	n=0
-	[ "$VERBOSE_MODE" -eq "1" ] && logger -s "Collecting NetJSON Monitoring data." \
-		-p daemon.info
+	log -i -v "Collecting NetJSON Monitoring data."
 	until [ "$n" -ge 5 ]; do
 		/usr/sbin/netjson-monitoring --dump "$MONITORED_INTERFACES" && break
 
-		if [ "$n" -eq 5 ]; then
-			[ "$VERBOSE_MODE" -eq "1" ] && logger -s "Collecting data failed!" -p daemon.err
-		fi
+		[ "$n" -eq 4 ] && log -e -v "Collecting data failed!"
 		n=$((n + 1))
 		sleep 5
 	done
@@ -105,8 +135,7 @@ save_data() {
 			echo "$data" >"$TMP_DIR/$filename"
 			# compress data
 			gzip "$TMP_DIR/$filename"
-			[ "$VERBOSE_MODE" -eq "1" ] && logger -s "Data saved temporarily." \
-				-p daemon.info
+			log -i -v "Data saved temporarily."
 		fi
 		# get process id of the process sending data
 		pid=$(pgrep -f "openwisp-monitoring.*--mode send")
@@ -116,8 +145,7 @@ save_data() {
 }
 
 handle_sigusr1() {
-	[ "$VERBOSE_MODE" -eq "1" ] && logger -s "SIGUSR1 received! Sending data." \
-		-p daemon.info
+	log -i -v "SIGUSR1 received! Sending data."
 	return 0
 }
 
@@ -126,8 +154,7 @@ send_data() {
 	while true; do
 		for file in "$TMP_DIR"/*; do
 			if [ ! -f "$file" ]; then
-				[ "$VERBOSE_MODE" -eq "1" ] && logger -s "No data file found to send." \
-					-p daemon.info
+				log -i -v "No data file found to send. Checking again in $INTERVAL seconds."
 				trap handle_sigusr1 USR1
 				# SIGUSR1 signal received, interrupt sleep and continue sending data
 				sleep "$INTERVAL" &
@@ -154,24 +181,19 @@ send_data() {
 			if [ -f "$filename" ]; then
 				data=$(cat "$filename")
 			else
-				[ "$VERBOSE_MODE" -eq "1" ] && logger -s "data file $filename not found." \
-					-p daemon.info
+				log -i -v "data file $filename not found."
 				continue
 			fi
 			while true; do
 				if [ "$failures" -eq "$MAX_RETRIES" ]; then
 					[ -f "$RESPONSE_FILE" ] && error_message="\"$(cat "$RESPONSE_FILE")\"" || error_message='"".'
-					if [ "$VERBOSE_MODE" -eq "1" ]; then
-						logger -s "Data not sent successfully. Response code is \"$response_code\"." \
-							"Error message is $error_message" \
-							-p daemon.err
-					elif [ "$FAILING" -eq "0" ]; then
+					log -e -v "Data not sent successfully. Response code is \"$response_code\"." \
+						"Error message is $error_message"
+					# check if agent was already passing or not to avoid repeating log messages
+					if [ "$FAILING" -eq "0" ]; then
 						FAILING=1
-						logger -s "Data not sent successfully. Response code is \"$response_code\"." \
-							"Error message is $error_message" \
-							"Run with verbose mode to find more." \
-							-t openwisp-monitoring \
-							-p daemon.err
+						[ "$VERBOSE_MODE" -ne "1" ] && log -e -n "Data not sent successfully. Response code is \"$response_code\"." \
+							"Run with verbose mode to find more."
 					fi
 					break
 				fi
@@ -179,38 +201,30 @@ send_data() {
 				response_code=$($CURL_COMMAND -H "Content-Type: application/json" -d "$data" "$url")
 				if [ "$response_code" = "200" ]; then
 					success=$((success + 1))
-					if [ "$VERBOSE_MODE" -eq "1" ]; then
-						logger -s "Data sent successfully." \
-							-p daemon.info
-					elif [ "$FAILING" -eq "1" ]; then
-						logger -s "Data sent successfully." \
-							-t openwisp-monitoring \
-							-p daemon.info
+					log -i -v "Data sent successfully."
+					# check if agent was already failing or not to avoid repeating log messages
+					if [ "$FAILING" -eq "1" ]; then
 						FAILING=0
 						rm -f "$RESPONSE_FILE"
+						[ "$VERBOSE_MODE" -ne "1" ] && log -i -n "Data sent successfully."
 					fi
 					# remove saved data
 					rm -f "$filename"
 					break
 				elif [ "$response_code" = "400" ]; then
-					logger -s "Data not sent successfully (HTTP status $response_code), discarding data." \
-						-t openwisp-monitoring \
-						-p daemon.err
+					log -i -n "Data not sent successfully (HTTP status $response_code), discarding data."
 					rm -f "$filename"
 					break
 				else
 					timeout=$(/usr/sbin/openwisp-get-random-number 2 15)
-					[ "$VERBOSE_MODE" -eq "1" ] && logger -s "Data not sent successfully. Retrying in $timeout seconds." \
-						-p daemon.warn
+					log -w -v "Data not sent successfully. Retrying in $timeout seconds."
 					failures=$((failures + 1))
 					if [ "$response_code" = "404" ]; then
 						# If we get a HTTP 404 response, it could mean that the device has been deleted from OpenWISP
 						# Controller. We check if openwisp-config agent is running to determine if the device has been
 						# deleted. If openwisp-config agent is not running, the monitoring agent will also exit.
 						if ! pgrep -x "openwisp-config" >/dev/null; then
-							logger -s "Giving up and shutting down: the device may have been deleted from OpenWISP Controller" \
-								-t openwisp-monitoring \
-								-p daemon.err
+							log -e -n "Giving up and shutting down: the device may have been deleted from OpenWISP Controller"
 							# get process id of the process collecting data
 							pid=$(pgrep -f "openwisp-monitoring.*--mode collect")
 							kill -SIGKILL "$pid"
@@ -236,17 +250,13 @@ wait_until_registered() {
 	if [ -n "$UUID" ] && [ -n "$KEY" ]; then
 		return 0
 	fi
-	logger -s "Waiting for device to register." \
-		-t openwisp-monitoring \
-		-p daemon.info
+	log -i -n "Waiting for device to register."
 	UUID=$(uci get openwisp.http.uuid 2>/dev/null)
 	KEY=$(uci get openwisp.http.key 2>/dev/null)
 	if [ -z "$UUID" ] || [ -z "$KEY" ]; then
 		return 1
 	fi
-	logger -s "Setting uuid and key." \
-		-t openwisp-monitoring \
-		-p daemon.info
+	log -i -n "Setting uuid and key."
 	export UUID KEY
 }
 
@@ -256,9 +266,7 @@ bootup_delay() {
 		if [ "$BOOTUP_DELAY" -ne "0" ]; then
 			# get a random number between zero and $BOOTUP_DELAY
 			DELAY=$(/usr/sbin/openwisp-get-random-number 0 "$BOOTUP_DELAY")
-			logger "Delaying initialization of the monitoring agent for $DELAY seconds." \
-				-t openwisp-monitoring \
-				-p daemon.info
+			log -i -n "Delaying initialization of the monitoring agent for $DELAY seconds."
 			sleep "$DELAY"
 		fi
 		# send bootup hotplug event
@@ -329,8 +337,7 @@ main() {
 				shift
 				;;
 			-*)
-				echo "Invalid option: $1"
-				exit 1
+				echoerr "Invalid option: $1."
 				;;
 			*) break ;;
 		esac
@@ -338,6 +345,8 @@ main() {
 	done
 
 	INTERVAL=${INTERVAL:-300}
+	INTERVAL="$(time_to_seconds "$INTERVAL")"
+	[ -z "$INTERVAL" ] && echoerr "Interval is invalid. Use time value(eg: '10', '2m', '3h', '1d')"
 	REGISTRATION_INTERVAL=$((INTERVAL / 10))
 	VERBOSE_MODE=${VERBOSE_MODE:-0}
 	BOOTUP_DELAY=${BOOTUP_DELAY:-10}
@@ -366,7 +375,7 @@ main() {
 		RESPONSE_FILE="$TMP_DIR"/response.txt
 		set_url_and_curl && send_data
 	else
-		echoerr "The supplied mode is invalid. Only send and collect are allowed"
+		echoerr "The supplied mode is invalid. Only send and collect are allowed."
 	fi
 }
 
diff --git a/openwisp-monitoring/files/monitoring.init b/openwisp-monitoring/files/monitoring.init
index 2f4807b..97f32ad 100755
--- a/openwisp-monitoring/files/monitoring.init
+++ b/openwisp-monitoring/files/monitoring.init
@@ -4,97 +4,70 @@
 
 # shellcheck disable=SC2034
 START=99
-STOP=15
+
 USE_PROCD=1
 PROG="/usr/sbin/openwisp-monitoring"
 PROG_NAME="OpenWISP monitoring daemon"
 
-time_to_seconds() {
-	time=$1
-
-	{ [ "$time" -ge 1 ] 2>/dev/null && seconds="$time"; } \
-		|| { [ "${time%s}" -ge 1 ] 2>/dev/null && seconds="${time%s}"; } \
-		|| { [ "${time%m}" -ge 1 ] 2>/dev/null && seconds=$((${time%m} * 60)); } \
-		|| { [ "${time%h}" -ge 1 ] 2>/dev/null && seconds=$((${time%h} * 3600)); } \
-		|| { [ "${time%d}" -ge 1 ] 2>/dev/null && seconds=$((${time%d} * 86400)); }
+add_option() {
+	# shellcheck disable=SC3043
+	{
+		local cfg="$1"
+		local flag="$2"
+		local option="$3"
+		local default="$4"
+		local value
+	}
 
-	echo "$seconds"
-	unset seconds
-	unset time
+	config_get value "$cfg" "$option" "$default"
+	[ -n "$value" ] && procd_append_param command "$flag" "$value"
 }
 
 start_service() {
 	# for openwisp-config
 	config_load openwisp
-	config_get base_url http url
-	config_get uuid http uuid
-	config_get key http key
-	config_get cacert http cacert
-	config_get capath http capath
-	config_get_bool verify_ssl http verify_ssl "1"
-	config_get respawn_threshold http respawn_threshold
-	config_get respawn_timeout http respawn_timeout
-	config_get respawn_retry http respawn_retry
-
-	[ -n "$base_url" ] && base_url="--url $base_url"
-	[ -n "$uuid" ] && uuid="--uuid $uuid"
-	[ -n "$key" ] && key="--key $key"
-	[ -n "$cacert" ] && cacert="--cacert $cacert"
-	[ -n "$capath" ] && capath="--capath $capath"
-	[ -n "$verify_ssl" ] && verify_ssl="--verify_ssl $verify_ssl"
-
-	if [ -z "$base_url" ]; then
-		logger -s "url is not set, please add it to /etc/config/openwisp" \
-			-t openwisp-monitoring \
-			-p daemon.err
-		exit 1
-	fi
-
-	# for openwisp-monitoring
+
+	respawn_threshold=$(config_get http respawn_threshold)
+	respawn_timeout=$(config_get http respawn_timeout)
+	respawn_retry=$(config_get http respawn_retry)
+
+	procd_open_instance "openwisp-monitoring_send_data"
+	procd_set_param command $PROG
+
+	add_option "http" "--url" url
+	add_option "http" "--uuid" uuid
+	add_option "http" "--key" key
+	add_option "http" "--cacert" cacert
+	add_option "http" "--capath" capath
+	add_option "http" "--verify_ssl" verify_ssl "1"
+
 	config_load openwisp-monitoring
-	config_get monitored_interfaces monitoring monitored_interfaces "*"
-	config_get interval monitoring interval "300"
-	config_get_bool verbose_mode monitoring verbose_mode "0"
-	config_get required_memory monitoring required_memory "0.05"
-	config_get max_retries monitoring max_retries "5"
-	config_get bootup_delay monitoring bootup_delay "10"
-
-	interval="$(time_to_seconds "$interval")"
-	if [ "$interval" -lt 1 ]; then
-		logger -s "Interval is invalid. Use time value(eg: '10', '2m', '3h', '1d')" \
-			-t openwisp-monitoring \
-			-p daemon.err
-		exit 1
-	fi
-	interval="--interval $interval"
-	verbose="--verbose_mode ${verbose_mode:-0}"
-	required_memory="--required_memory $required_memory"
-	max_retries="--max_retries $max_retries"
-	bootup_delay="--bootup_delay $bootup_delay"
 
-	procd_open_instance "openwisp-monitoring_collect_data"
-	# shellcheck disable=SC2086,SC2154
-	procd_set_param command $PROG $interval $verbose $required_memory --mode collect --monitored_interfaces "$monitored_interfaces"
+	add_option "monitoring" "--verbose_mode" verbose_mode "0"
+	add_option "monitoring" "--max_retries" max_retries "5"
+	add_option "monitoring" "--interval" interval "300"
+	procd_append_param command "--mode" "send"
+
 	procd_set_param respawn "${respawn_threshold:-3600}" "${respawn_timeout:-5}" "${respawn_retry:-5}"
-	[ "$verbose_mode" -eq "1" ] && procd_set_param stdout 1 && procd_set_param stderr 1
 	procd_close_instance
 
-	procd_open_instance "openwisp-monitoring_send_data"
-	# shellcheck disable=SC2086
-	procd_set_param command $PROG $base_url $uuid $key $cacert $capath $verify_ssl $interval $verbose $max_retries $bootup_delay --mode send
+	procd_open_instance "openwisp-monitoring_collect_data"
+	procd_set_param command $PROG
+
+	add_option "monitoring" "--monitored_interfaces" monitored_interfaces "*"
+	add_option "monitoring" "--required_memory" required_memory "0.05"
+	add_option "monitoring" "--verbose_mode" verbose_mode "0"
+	add_option "monitoring" "--interval" interval "300"
+	procd_append_param command "--mode" "collect"
+
 	procd_set_param respawn "${respawn_threshold:-3600}" "${respawn_timeout:-5}" "${respawn_retry:-5}"
-	[ "$verbose_mode" -eq "1" ] && procd_set_param stdout 1 && procd_set_param stderr 1
 	procd_close_instance
 
-	logger -s "$PROG_NAME started" \
-		-t openwisp-monitoring \
-		-p daemon.info
+	logger -s "$PROG_NAME started." -t openwisp-monitoring -p daemon.info
 }
 
 stop_service() {
-	logger -s "$PROG_NAME stopping" \
-		-t openwisp-monitoring \
-		-p daemon.info
+	logger -s "$PROG_NAME stopping." -t openwisp-monitoring -p daemon.info
 }
 
 service_triggers() {