The HART Communicator informs the user that the maintenance flags have been reset when the transmitter has replied to the reset command. The user must acknowledge this information by pressing OK to continue.

The user is then notified that the loop may now be returned to automatic control. After the user presses OK the HART Communicator returns to the Diagnostics screen.

The user must use the left arrow to return to the Diag/Service screen.

If the user selects Loop test from the Diag/Service screen, a procedure will begin that will allow the user to set the loop current to a value desired to perform a loop test function.

When the user selects the Loop test option, the HART Communicator displays the warning message that the loop should be removed from automatic control during this procedure.

The user is presented with four selections as shown on the screen. The 4mA and 20mA selections will set those values while selecting Other will require the user to input the exact loop current that is desired. The procedure will be exited if the user selects End. The example shows the user selection 4mA. The user must press ENTER before the procedure continues.

The HART Communicator will then command the transmitter to set the loop current to 4mA and then it will dynamically read the value of loop current that the transmitter has applied. To return to the previous screen, the user must press OK. The procedure is exactly the same for the 20mA selection option

If the user wishes to specify a loop current other than 4mA or 20mA, he must select the option Other and then press the ENTER key.

The user must then input the exact value of loop current desired. After entering the value, he must press ENTER before the procedure continues. For example, the value

12.00is input on the screen to the

left.

The HART Communicator will then command the transmitter to set the loop current to 12.00mA and then it will dynamically read the value of loop current that the transmitter has applied. To return to the previous screen, the user must press OK.

To exit the Loop test procedure, the user must select the option End and then press the ENTER key.

The HART Communicator then issues the command to the transmitter to return to the measurement mode as it was before entering Loop test.

The user is then notified that the loop may now be returned to automatic control. After the user presses OK the HART Communicator returns to the Diag/ Service screen.

If the user selects Calibration from the Diag/Service screen, a number of menu selections are available. The user must now select the type of calibration he desires to perform.

The Scaled D/A trim will adjust the transmitter so that its current output at the 4.00mA and 20.00mA output values will agree with the plant standard current meter.

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Emerson LTM-300 manual