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modbus_protocol [2019/01/09 14:16] (current)
emozolyak created
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 +====== Modbus ======
 +In WebHMI, such syntax of addressing ModBus (RTU/​ASCII/​TCP) registers is defined:
 +^Register address ^Description ^Data type^ Read(FC((FC - function code used)))/​Write(FC)^
 +|Cx |Coils. X — output number (valid range is 0..65535). Examples: C1, C3, C44 |Bit| Read(0x01)/​Write(0x05)|
 +|DIx |Discrete Inputs. X — input number (valid range 0 ..65535). Examples: DI1, DI3, DI44, DI45000 |Bit |Read(0x02)/​—|
 +|HRx |Holding Registers. X — register address (valid range 0..65535). Examples: HR1, HR3, HR44, HR65043 |Bit,​ Byte, Word, Double Word |Read(0x03)/​Write(0x06)|
 +|MHRx |Identical to HRx. The difference is that the writing in such registers occurs using the Modbus function No. 16 (Preset Multiple Register). |Bit,​ Byte, Word, Double Word |Read(0x03)/​Write(0x16)|
 +|IRx |Input Registers. X — register address (valid range 0..65535). Примеры:​ IR1, IR3, IR44, IR65043 |Bit,​ Byte, Word, Double Word |Read(0x04)/​—|
 +  ATTENTION! By default, for double word reading, two queries each by one word will be used. To explicitly set 
 +  double-word ​ reading with one query (multiple read), you must enable grouping in the connection properties.

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