Logstash can not parse azure activity logs

Hello,
Found this topic. Best way to parse json input?

described there method works,

input {
exec {
command => "type c:\PT1H.json"
codec => json
interval => 60
}
}

but it reads only one entry from json and repeats this json record each time during the mentioned interval. (duplicates the same document in loop).

Is there any method to read all entire json document from the begin till its end without time duplicates?