Instruction manual

58 RFT9739 Field-Mount Transmitter Instruction Manual
Startup
continued
4. Zero the transmitter in any of five ways:
• Press and hold the ZERO button for at least ten seconds or until the
LED remains on continuously.
Figure 6-1
, page 58, shows the
location of the button on the electronics module.
• If the transmitter has a display, use the Scroll knob to advance to the
mass flow rate screen or volume flow rate screen, then rotate and
hold the Reset knob for at least ten seconds. (In the rate screens,
"RATE" appears in the upper left corner of the screen.)
• An external contact closure can be used for transmitter zeroing.
(Refer to
Section 5.8
, page 46, for wiring instructions.) Close the
contact for at least ten seconds.
• Issue an auto zero command using a HART Communicator, a
HART-compatible or Modbus-compatible master controller, or the
ProLink software program.
• Issue a "zero trim" command with the AMS program.
During transmitter zeroing, the diagnostic LED remains on continuously.
See
Figure 6-1
. If the transmitter has a display, it reads "Sensor OK CAL
IN PROGRESS". (It might be necessary to scroll through the process
variable screens more than once to view this message.) The default zero
time will range from 20 to 90 seconds, depending on the sensor.
After the zeroing procedure has been completed, the LED again blinks
ON once per second to indicate normal operation. If the transmitter has
a display, the mass flow rate or volume flow rate screen reappears, and
the blinking "Msg" (message) indicator appears in the lower right corner.
To clear the message indicator, scroll to the message screen, which
should read "Sensor OK *ERROR CLEARED*".
Figure 6-1.
Diagnostic LED and zero
button
Diagnostic LED
Zero button