ABB 266 MODBUS User Manual page 76

Setting the DP offset to zero
Perform the following steps to set the current differential pressure value to zero:
1. Disable transmitter write protection security if enabled. DIP switch 5 must be OFF before continuing. To disable write
protection follow the instructions in section 5.3.2, Disable write protection.
2. Isolate the transmitter from the measurement stream by decommissioning the transmitter using the procedure in section
5.11, Removing the transmitter from service.
3. Verify that the manifold equalizer and vent valves (Figure 47, items A, B, and C, page 58) are open and that the high (H)
and low (L) tap valves are closed.
4. Press the right soft key to access the HMI menu.
5. Use the key pad to locate and select Device Setup.
6. Check the DP reading on the HMI display.
a. If DP = 0, correction is not required.
If the DP ≠ 0, proceed as follows:
b.
7. Use the key pad to locate and select Set Diff. Press. Bias > Set DP to Zero.
a. On the HMI display, the current differential pressure reading is displayed.
b. Use the key pad to select OK. The progress bar will fill up and the value will change to zero.
8. Once completed, use the left key to navigate to the Operator screen. Observe that the DP value is now zero.
Return the transmitter to service using the procedure in section 4.3.4, Putting the transmitter in service.
68 | 266 MODBUS® multivariable transmitter User manual 2105216 Rev. AB
5 Service and maintenance