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A-2

Rosemount Inc

NOTE

A HART Communicator requires a loop resistance between 250 and 1100 ohms. Do

not communicate with the transmitter when power is below 12 V dc at the

transmitter terminals.

Temperature Limits

Failure Mode

The values at which the transmitter drives its output in failure mode depends on

whether it is configured to standard, NAMUR-compliant (NAMUR

recommendation NE 43, June 1997), or custom operation. The values for standard

and NAMUR-compliant operation are as follows:

Table A-5. Standard and NAMUR-Compliant Operation Parameters

Custom Alarm and Saturation Levels

Custom factory configuration of alarm and saturation level is available with option

code C1. These values can also be configured in the field using a HART

Communicator.

Operating Limit Storage Limit

°F °C °F °C

With LCD Meter

–4 to 185 –20 to 85 –50 to 185 –45 to 85

Without LCD Meter

–40 to 185 –40 to 85 –58 to 248 –50 to 120

Standard NAMUR-Compliant

Linear Output: 3.9 ≤ I ≤ 20.5 mA 3.8 ≤ I ≤ 20.5 mA

Fail high: 21.0 ≤ I ≤ 23.0 mA (Default) 21.0 ≤ I ≤ 23.0 mA

Fail low: I

≤ 3.75 mA I ≤ 3.6 mA

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Emerson Rosemount 644h Handbuch Seite 38