schneiderInstruction MI 021-390 February 2016 I/A Series® Magnetic Flow Transmitter Model IMT25 Operation, Configuration, and Calibration

of the loop. You may not edit them in this mode. To step through the displays of the following 

parameters, use the up/down arrow keys: 

 Mode — Shows the present operating mode: On-Line, Off-Line, Override, or 

Calibrate. This will normally display On-Line. The other modes will only be 

displayed if someone else has changed the mode with an I/A Series Workstation,

PC-Based Configurator, HART Communicator, or fieldbus host. Off-Line means

that it has been taken off-line; Override, that the measurements cannot be relied 

upon because one or more of the outputs is at a preset value; and Calibrate, that the 

transmitter is in Calibration mode.

 Alarm — Shows the most current active alarm. If there are no active alarms but 

something is in the history buffer, the display reads Alarms In Buffer. If there are 

no active alarms and nothing in the buffer, display reads No Alarms. 

 Diagnostics — Shows No Diag, Diag Existed, or Diag Exists. If a diagnostic 

problem exists, the second line identifies the problem. Help is available with the 

Shift + Help keys. An active diagnostic problem cannot be cleared; the problem 

must be corrected. Diag Existed means a diagnostic error did occur, but the 

condition has cleared and the transmitter is working correctly. However, the Diag icon 

will remain on the display until the diagnostic has been acknowledged. To clear, the 

transmitter must be in the Status mode with the diag window displayed. Then use the 

Shift + Ack keys.

 Digital Output — If the transmitter output is in Digital Output mode, the display 

shows whether the transmitter is configured for Unidirectional or BiDirectional flow. 

If the transmitter is not in Digital Output mode, the screen is not displayed.

NOTE

Digital and Analog Output are mutually exclusive. Only one of the two are displayed 

at any one time.

 Analog Output — If the transmitter output is in Analog Output mode, the display 

shows whether the transmitter is configured for U (unidirectional), U/M1

(unidirectional multirange-range 1), U/M2 (unidirectional multirange-range 2, U/M3

(unidirectional multirange-range 3), B/D (bidirectional dual range), or B/S

(bidirectional split range). If the transmitter is not in Analog Output mode, the screen 

is not displayed.

NOTE

Digital and Analog Output are mutually exclusive. Only one of the two are displayed 

at any one time.

Table 5. Analog Output Configuration

Display Interpretation

U UniDirectional Flow Single Range

U/M1 UniDirectional Flow Multi-Range

Range 1 Active

U/M2 UniDirectional Flow Multi-Range

Range 2 Active

U/M3 UniDirectional Flow Multi-Range

Range 3 Active

B/D BiDirectional Flow Dual Range

B/S BiDirectional Flow Split Range

(mA reading less than 12 indicates reverse flow, greater than 12, 

positive flow)

**UNKNOWN** Multi-Range is configured, but both contact inputs used to select 

the active range are in inactive state

 AZL Detect (Empty Pipe Det) — The intent of the AutoZeroLock Detection 

(Empty Pipe Detection) feature is explained in “AutoZeroLock (Empty Pipe)” on 

page 53. 

If the AutoZeroLock (Empty Pipe) detector is configured On, the display shows:

EPD Inactive, EPD Active, or EPD Needs Setpnt (FoxCom)

AZL Inactive, AZL Active, or AZL Needs Setpnt (HART)

Inactive, Active, or AZL Needs Cal (Fieldbus).

When AZL (EPD) is active, the outputs are locked at zero. If AZL (EPD) is 

configured Off, the status display shows Off.

! WARNING

Do not take any action that can cause danger to personnel or damage to equipment 

based on the assumption that a pipe is empty or full because of an AutoZeroLock 

(Empty Pipe Detection) indication.

 AZL Count (Empty Pipe Cnt) — Shows the cumulative count (maximum of 255) of 

AZL (empty pipe) conditions that have occurred since the last reset. To reset the 

count to zero, press Shift + Reset Note that in some cases several counts may 

occur for one emptying of the pipeline.

 Noise Reduction — Shows whether the noise reduction function is configured On or 

Off.

Write Protection — Shows whether the Write Protection dip switch is in the On position so that 

no Setup (configuration) changes may be made. This feature is usually only used in custody 

transfer applications or for another reason that you want to assure that the configuration is not 

changed. For the procedure to change the setting of this switch, see MI 021-387.