Emerson manual Alarms I/O TRANSDUCER BLOCK, Rosemount 848L, Reference Manual

Reference Manual

00809-0100-4696, Rev AA September 2004

Rosemount 848L

Alarms

I/O TRANSDUCER BLOCK

Use the following steps to configure the alarms, which are located in the Resource Block.

1.Set the resource block to OOS.

2.Set WRITE_PRI to the appropriate alarm level (WRITE_PRI has a selectable range of priorities from 0 to 15. Set the other block alarm parameters at this time.

3.Set CONFIRM_TIME to the time, in 1/32 of a millisecond, that the device will wait for confirmation of receiving a report before trying again (the device does not retry if CONFIRM_TIME is 0).

4.Set LIM_NOTIFY to a value between zero and MAX_NOTIFY.

LIM_NOTIFY is the maximum number of alert reports allowed before the operator needs to acknowledge an alarm condition.

5.Enable the reports bit in FEATURE_SEL.

6.Set the resource block to AUTO.

The 848L is ordered with either Dry Contact, VDC or NAMUR Inputs. Each input can have a filter which determines the minimum time a contact needs to be at a given state to be acknowledged as a state change.

The following procedure allows the sensors to be configured:

1.Set MODE_BLK.TARGET to OOS

2.For each Input “n” select the parameter IN_n_CONFIG.FILTER a. Select the desired filter time in the range of 0 to 128msec

3.Set MODE_BLK.TARGET to AUTO

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