Eaton CROUSE-HINDS Series Instruction Manual page 37

INM F809F-Plus (DTM) Rev 1.8
• Device signal amplitude limits
The physical layer standard IEC 61158-2 specifies transmit levels of 750 mV to
1000 mV under test conditions with two terminators. Under plant conditions, the
actual values will differ from segment to segment, and under some
circumstances even significantly.
Values down to 550 mV and up to 1200 mV should however cover
most applications.
The default limits are set to the following:
Alarm hysteresis (no alarm > alarm > no alarm) is 10 mV. Note that the limit values
have to be in rising sequence at all times:
Low-low-limit ≤ low-limit < high-limit ≤ high-high-limit
and high limit must be at least 20 mV higher than low limit.
We recommend that after successful commissioning, the device low limit is set to
75 % of current value and device high limit to 125 % of current value.
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