KROHNE MFC 400 Modbus - Manual (Page 29)

APPLICATION SEQUENCES
6
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MFC 400
www.krohne.com 05/2013 - 4002525102 - AD Modbus MFC 400 R02 en
6.2 Zero calibration
• The example assumes slave address 1 for Modbus telegram.
• Substitute "xx xx xx xx" with value read from Input Register 20001.
1 Start 6a Failed - Sensor not measuring
2 Start Zero Calibration 6b Failed - Zero too high
2a Set Coil 2000 (0x07D0)
MB-Telegram: 01 05 07 D0 FF 00 + CRC 6c successful
3 Check Status Of Zero Calibration 7 Calibration Failure
3a Read Coil 2000 (0x07D0)
MB-Telegram: 01 01 07 D0 00 01 + CRC 8 Read new Zero Flow Offset
4a running 8a Read Input Register 20001 (0x4E21)
MB-Telegram: 01 04 4E 21 00 02 + CRC
4b ready 9 Write new Zero Flow Offset
5
5a Read Result
Read Input Register 20000 (0x4E20)
MB-Telegram: 01 04 4E 20 00 01 + CRC 9a Write Holding Register 46000 (0xB3B0)
MB-Telegram:
01 10 B3 B0 00 02 04 xx xx xx xx + CRC
10 Apply Changes
10a Set Coil 1002 (0x03EA)
MB-Telegram: 01 05 03 EA FF 00 + CRC
11 Calibration Done