The message log is the eMon Energy's Diary. It makes notes about various events that occur, both ordinary and unusual. These messages can be helpful in understanding what is happening with the device, or to provide insight into why something doesn't appear to be working as it should.
The primary method of accessed the message log is by hovering over the Tools main menu button and clicking the Message Log button. The config utility will cause your browser to download and display the most recent 10000 characters in the log. You can access the entire log by using the File Manager app to download the file /emon/emonmsgs.txt and viewing with a text file editor.
With the exception of the first messages after startup, all of the messages in the log will have a date and time stamp. Messages issued by one of the eMon Energy Services will begin with the name of the service followed by a colon, as in this message issued from the datalog Service indicating it has successfully started.
12/23/17 21:57:06 dataLog: service started.
While it would be impossible to maintain a list of all of the possible messages, the messages issued at startup are pretty straightforward and provide a lot of information.
** Restart ** SD initialized. 1/08/19 19:39:43z Real Time Clock is running. Unix time 1546976383 1/08/19 19:39:43z Power failure detected. 1/08/19 19:39:43z Reset reason: External System 1/08/19 19:39:43z ESP8266 ChipID: 427289 1/08/19 19:39:43z eMon Energy revision 4.9, firmware version 02_03_20 1/08/19 19:39:43z SPIFFS mounted. 1/08/19 14:39:44 Local time zone: -5:00 1/08/19 14:39:44 Using Daylight Saving Time (BST) when in effect. 1/08/19 14:39:44 device name: eMon 1/08/19 14:39:47 Connecting with WiFiManager. 1/08/19 14:39:53 MDNS responder started for hostname eMon 1/08/19 14:39:53 LLMNR responder started for hostname eMon 1/08/19 14:39:53 HTTP server started 1/08/19 14:39:53 WiFi connected. SSID=flyaway, IP=192.168.1.102, channel=1, RSSI -69db 1/08/19 14:39:53 timeSync: service started. 1/08/19 14:39:56 statService: started. 1/08/19 14:39:56 Updater: service started. Auto-update class is BETA 1/08/19 14:39:57 dataLog: service started. 1/08/19 14:39:57 dataLog: Last log entry 01/08/19 14:39:35 1/08/19 14:39:57 historyLog: service started. 1/08/19 14:39:57 historyLog: Last log entry 01/08/19 14:39:00 1/08/19 14:39:58 influxDB: started, url=192.168.1.101:8086, db=eMon, interval=10 1/08/19 14:39:58 Updater: Auto-update is current for class BETA. 1/08/19 14:39:58 influxDB: Start posting at 01/08/19 14:39:40
Some things to look for:
Real Time Clock is running. Unix time 1546976383
Except for initial setup, the RTC should always be running. If it is not, suspect the battery needs replacement.
Power failure detected.
This indicates that power interrupted prior to the restart.
Reset reason: External System
This is the reason for the restart. External System is a normal cause. Reasons like WDT and Exception indicate program faults and, if frequent, should be posted to the support forum.
eMon Energy revision 4.9, firmware version 02_03_20
The hardware and firmware versions. Good to know if things go wrong, and also useful to get the corresponding version of this documentation.
Local time zone: -5:00
The local time zone specified in you config file. This message and all subsequent messages should be timestamped with local-time as opposed to UTC which was indicated in prior messages with by the suffix 'z'.
device name: eMon
This is the external name of the unit. It will be used as the hostname when connecting to WiFi and it is the name that you must use to access the device as in http://emon.local.
WiFi connected. SSID=flyaway, IP=192.168.1.102, channel=1, RSSI -69db
Indicates connection to WiFi and the IP address assigned. The RSSI is an indication of WiFi signal strength. A good number would be between -50 and -78 or so. If you are having WiFi problems, this metric along with the channel number can be helpful in resolving.
timeSync: service started.
All of the regular services will log their startup. Some will also provide additional information about their configuration or state. All messages from system services begin with the name of the service followed by a colon.