HART DD文件开发的一个例子
来源: | 阅读:1646次 | 2023/5/18 11:07:53
VARIABLE low_flow_cutoff { LABEL "Low flow cutoff"; HELP "Low Flow Cutoff: the value below which the process variable will indicate zero, to prevent noise or a small zero error being interpreted as a real flow rate."; TYPE FLOAT { DISPLAY_FORMAT "6.4f"; /* ##.#### */ } CONSTANT_UNIT "%"; HANDLING READ & WRITE; } MENU configure_input { LABEL "Configure input"; ITEMS { flow_units, /* variable */ rerange, /* edit-display */ low_flow_cutoff, /* variable */ flow_tube_config, /* menu */ } } COMMAND write_low_flow_cutoff { NUMBER 133; OPERATION WRITE; TRANSACTION { REQUEST { low_flow_cutoff } REPLY { response_code, device_status, low_flow_cutoff } } RESPONSE_CODES { 0, SUCCESS, [no_command_specific_errors]; 3, DATA_ENTRY_ERROR, [passed_parameter_too_large]; 4, DATA_ENTRY_ERROR, [passed_parameter_too_small]; 5, MISC_ERROR, [too_few_data_bytes_received]; 7, MODE_ERROR [in_write_protect_mode]; } }
这里是DDL的一个小示例,包括对变量的描述、访问该变量的Menu和向其写入新值的Command。
方括号[xxx]中的短语是指作为DD方案的一部分提供的常见短语标准词典,并提供了几种语言的现成翻译。
标点符号(大括号和分号)取自“C”编程语言。一旦你学会了,就很容易了!
任何介于/*和*/之间的内容都是注释。