Emerson 644 manual Turn-on Time, Power Supply, Alarms, Backup Link Active Scheduler LAS

Reference Manual

00809-0400-4728, Rev AA June 2011

Rosemount 644

Turn-on Time

Performance within specifications in less than 20 seconds after power is applied, when damping value is set to 0 seconds.

Status

If self-diagnostics detect a sensor burnout or a transmitter failure, the status of the measurement will be updated accordingly. Status may also send the PID output to a safe value.

Power Supply

Powered over FOUNDATION fieldbus with standard fieldbus power supplies. The transmitter operates between 9.0 and 32.0 Vdc, 11 mA maximum. The power terminals are rated to 42.4 Vdc max.

Alarms

The AI function block allows the user to configure the alarms to HI-HI, HI, LO, or LO-LO with a variety of priority levels and hysteresis settings.

Backup Link Active Scheduler (LAS)

The transmitter is classified as a device link master, which means it can function as a Link Active Scheduler (LAS) if the current link master device fails or is removed from the segment.

The host or other configuration tool is used to download the schedule for the application to the link master device. In the absence of a primary link master, the transmitter will claim the LAS and provide permanent control for the H1 segment.

FOUNDATION fieldbus Parameters

Schedule Entries	25(1)
Links	16(1)
Virtual Communications Relationships (VCR)	12(1)

(1) Minimum quantity.

Software Upgrade in the Field

Software for the 644 with FOUNDATION fieldbus will be easy to upgrade in the field. Users will be able to take advantage of software enhancements by loading new application software into the device memory.

A-5