User’s Manual
Rev1.0
Date:15/07/2015 User’s Manual
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6.5 The sequence of the float date bytes of instrument
Code setting C40 is used for setting the sequence of the float date bytes of instrument.
1: LL_LH_HL_HH the lower 16 bytes registers come first, the lower 8 bytes within the 16 bytes
registers come first.
eg: 100=0x00,0x00, 0xc8, 0x42
-100=0x00, 0x00, 0xc8, 0xc2
2: HH_HL_LH_LL the higher 16 bytes registers come first, the higher 8 bytes within the 16 bytes
registers come first.
eg: 100=0x42,0xc8,0x00,0x00
-100=0xc2,0xc8 ,0x00,0x00
3: LH_LL_HH_HL the lower 16 bytes registers come first, the higher 8 bytes within the 16 bytes
registers come first.
eg: 100=0x00,0x00,0x42,0xc8
-100=0x00,0x00,0xc2,0xc8
4: HL_HH_LL_LH the higher 16 bytes registers come first, the lower 8 bytes within the 16 bytes
registers come first.
eg: 100=0xc8,0x42,0x00,0x00
-100=0xc8,0xc2,0x00,0x00
6.6 Modbus error reponse
When the host sends a command and asks for a correct reponse, one of below four is going to
happen:
1) If the command from the host is correct and processable, the flow meter will give a correct reponse.
2) If the flowmeter failed to receive the command due to a communication failure, the flowmeter will
not response. . The host will process an overtime commend.
3) If the flowmeter received a command, but detected parity, the error of LRC and CRC will cause no
reponse. The host will process an overtime commend.
4) If the flowmeter recived a correct command, but can not process it (read or write a none-existing
register etc.), the flowmeter will send a error reponse
A error reponse has two byte sections to show its difference from a correct reponse.
Function code section: In a correct reponse, the flowmeter will copy the origin function code sent from
the host, and the highest bytes of them are all 0(all function codes are smaller than 0x80). In a error
reponse, the flowmeter will set the highest bytes to 1. The host can detect the error code and know the
content of the error when it detect that the highest bytes of function codes are 1.
Value section: In a error reponse, the flowmeter will reply a byte as the error code to definite the
content of the error. Pleaes reference to the chart below for the error codes and its definition:
