Hach 900 MAX manual Appendix B Data Log, Logging Intervals, Power Save Mode, Continuous Mode

Appendix B

Data Log

From the Main Menu, select SETUP > ADVANCED OPTIONS > DATALOG.

The sampler can record up to 116,000 readings from any or all input channels and store them in solid state, battery-backed memory for later viewing or retrieval.

This option allows the selection of channels to log, how often to log, and how to treat the memory when it becomes full (Slate or Wrap).

The sampler has two data logging modes:

•Power Save Mode

•Continuous Mode

Logging Intervals

Logging Intervals are designed to optimize the available memory so that readings can be logged for a longer period of time. A logging interval is the time period over which readings are taken and then averaged.

Power Save Mode

Power Save Mode is automatically initiated upon power-up if a battery is installed on the sampler. When operating in Power Save Mode, the sampler microprocessor spends most of its time asleep conserving battery power. Once per minute, the sampler wakes up, logs the readings from all enabled input channels, performs any other necessary functions and then goes back to sleep.

Selecting a five-minute logging interval means that the readings are still taken every minute but the data is not logged until the five-minute logging interval is complete. At that time the readings are averaged over the previous five minutes and that average is logged

Continuous Mode

Continuous Mode is automatically initiated upon power up if ac power is supplied. The microprocessor stays awake at all times taking readings every second. At the end of the specified logging interval, the readings are averaged over the previous interval and stored in memory. If a one-minute logging interval is selected, a reading will be taken approximately every second but no data is logged until the logging interval ends. At that time, the readings are averaged over the logging interval and only the average is logged.

If a five-minute logging interval is selected, readings are still taken every second but the data are not logged until the five-minute logging interval ends. At that time, the readings are averaged over the previous five minutes and the average is logged.

Extended Power Mode

Extended Power Mode provides additional battery life by keeping a sampler powered down during the entire logging interval. For example, if a logging interval of five minutes is selected, the sampler stays asleep until the five minutes has expired. It then wakes up, takes a reading, logs it in memory and goes back to sleep for another five minutes. The sampler does not wake up every minute as it does in normal

	Page 119
8990apdx_pfeatures.fm	Programming Features