成本最低且变化最小，则来源于系统脚本，底盘格式，现场布线，逻辑控制和文件的持有。
Costs are reduced and changes are minimized because the system footprint, chassis format, field wiring, control logic, and documentation are retained.
成本最低且变化最小，则来源于系统脚本，底盘格式，现场布线，逻辑控制和文件的持有。
Costs are reduced and changes are minimized because the system footprint, chassis format, field wiring, control logic, and documentation are retained.
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