Emerson Process Management 2088 FAILURE MODE AND SECURITY JUMPERS Failure Mode, Jumper Locations

Reference Manual

00809-0100-4690, Rev EA March 2007

Rosemount 2088 and 2090

Figure 3-10. Rosemount 2088 Smart Signal Wiring Terminals.

FAILURE MODE AND SECURITY JUMPERS

Failure Mode

Positive

Negative

Test

As part of normal operation, the Rosemount 2088/2090 Smart Pressure Transmitter continuously monitors its own operation. This automatic diagnostic routine is a timed series of checks repeated continuously. If the diagnostic routine detects a failure in the transmitter, the transmitter drives its output either below or above specific values depending on the position of the failure mode jumper or switch.

The values to which 4–20 mA transmitters drive their output in failure mode depend on whether they are factory-configured to standard or NAMUR-compliant operation. The values for each are as follows:

Standard Operation

Linear output: 3.9 ≤ I ≤ 20.8 mA

Fail low: I ≤ 3.75 mA

Fail high: I ≥ 21.75 mA

NAMUR-Compliant Operation (Option Code C4)

Linear output: 3.8 ≤ I ≤ 20.8 mA

Fail low: I ≤ 3.6 mA

Fail high: 21.0 ≤ I ≤ 23.0 mA

To determine the failure mode configuration of your transmitter, review the failure mode options using a 275 HART Communicator.

NOTE

The failure mode configuration, whether standard or NAMUR-compliant, is configured at the factory and can not be changed in the field.

Jumper Locations Without a meter installed

The failure mode alarm jumper is located on the front side of the electronics module just inside the electronics housing cover and is labeled ALARM (See Figure 3-11). Do not remove the transmitter cover in explosive atmospheres when the circuit is alive. Both covers must be fully engaged to meet explosion-proof requirements.

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