Owner's manual

FACTORYTALK HISTORIAN ME MODULE USER’S GUIDE

104

In the preceding illustration, values A, D, and C are reported to the FactoryTalk

Historian ME server. Value A is the last reported value, and values B and C fall

within the exception deadband. However, value D falls outside the deadband, so the

Data Collection service reports value D as well as the previous value (in this case,

value C).

The Data Collection service uses the point’s Exception Deviation (ExcDev),

Exception Min (ExcMin), and Exception Min (ExcMax) attributes to decide whether

to report the new value to the FactoryTalk Historian ME server:

Field Description

ExcDev

Determines how much a point's value needs to change before the

Data Collection service sends it to the FactoryTalk Historian ME

server. For example, a 12 bit A/D converter can never be more

precise than 1 part in 4096.

is the

last

reported

value.

TIME

TEMPERATURE

ExcMax

ExcDev

The value DD falls outside the

deadband so the Data Collection

service reports it and the previous

value to FactoryTalk Historian ME.