Honeywell SMV800 User Manual page 187

Correcting the Lower Range Value (LRV) for Differential Pressure:
Calibrate using SMV Modbus application:
1. Connect power supply and RS485 connectors to the signal terminals of the
Transmitter's terminal block.
2. Connect the precision pressure source to the high-pressure side of the DP-type
Transmitter.
3. Turn on the power supply, and allow the Transmitter to become stable.
4. Launch SMV Modbus application, connect to the device and go to the DP
Calibration screen as show below. DP Calibration is available at Maintenance-
>Calibration and Correction Records->Differential Pressure Calibration.
5. Adjust the pressure source to apply pressure equal to the LRV (0%), and
6. Click on "DP LRV Correct" button. follow the on-screen prompts.
Calibrate manually by writing to Modbus registers:
1. Write the LRV value for which the correction is required to the registers 669-770.
2. Write the date in the DDMMYY-- format in the calibration time and date register.
(Register address 125-126)

The date to be written as month and day followed by the year.

Year to be entered as year -1900.
For example, to enter calibration date as June 10
0x0A067600
3. Adjust the PV input Pressure to the exact value of the LRV.
4. Write to single coil address 3 as ON
Correcting the Upper Range Value (URV) for Differential Pressure:
Calibrate using SMV Modbus application:
1. Connect power supply and RS485 connectors to the signal terminals of the
Transmitter's terminal block.
2. Connect the precision pressure source to the high-pressure side of the DP-type
Transmitter.
3. Turn on the power supply, and allow the Transmitter to become stable.
4. Launch SMV Modbus application, connect to the device and go to the DP
Calibration screen as show below. DP Calibration is available at Maintenance-
>Calibration and Correction Records->Differential Pressure Calibration.
5. Adjust the pressure source to apply pressure equal to the URV (100%), and
6. Click on "DP URV Correct" button. follow the on-screen prompts.
Revision 1.0 SMV800 Modbus User's Guide
th
2018 write to register 125-126 as
Page 175