A received message is not necessarily a fresh measurement
A dashboard can display a believable 压力 or 液位 value while the field device has stopped reporting. Begin the acceptance specification with three separate states: connected, recently received and measurement valid. A connection indicator alone does not establish the age or quality of the displayed sample. The checks in this article are recommended application design choices, not a claim about a particular WESIVO firmware implementation.
Record measurement time and receipt time separately
Ask for the actual telemetry format. Where available, retain the field measurement timestamp and the receiving system timestamp as separate values. Document the time zone, clock synchronisation and behaviour after a device restart. If a device has no trustworthy clock, label the sample by receipt time and record that limitation. Do not rename receipt time as measurement time.
Define units and validity at the interface
For each field, agree its physical quantity, engineering unit, scale factor and permitted operating range. Clarify whether a 液位 field means 传感器-to-surface distance, height above a reference or calculated volume. Agree how a missing field, invalid value and device diagnostic are represented. Keep unavailable measurements visibly unavailable rather than silently substituting zero. MQTT transport does not replace this project field map.
Separate delivery semantics from application records
OASIS defines MQTT QoS 1 as delivery at least once, so duplicates are possible. Retained messages can provide stored state to a new subscriber; they are not automatically recent readings. Neither mechanism validates 传感器 accuracy. At application 液位, agree duplicate handling using a suitable device identity and sample identifier or sequence where available. Avoid relying solely on an MQTT packet identifier as a permanent historical-record key.
Agree when data becomes stale
Choose the stale-data threshold from the expected reporting interval, communication behaviour and application needs. Document it as a project value rather than publishing one universal interval for all 无线 仪表. Show the latest valid sample time and age beside the reading. Decide separately how the application treats connection loss, a late sample and a live connection carrying invalid measurement data.
Test recovery and customer isolation
During controlled commissioning, test reporting interruption, reconnection and delayed or repeated samples. Confirm that late data does not silently replace a newer current reading, and that the history policy is documented. Test that each customer account can access only its assigned devices. Account mapping and access control must be implemented in the platform; they cannot be inferred from the presence of a topic name.
Apply the checklist to WESIVO 选型
The published WESIVO 728W information lists MQTT and selectable LoRa, Wi-Fi or Bluetooth interfaces. Confirm the actual ordered interface, protocol version and supported behaviour before integration. The 4G radar models require a separate protocol review. For an RFQ, provide the receiving platform, a required field map, reporting expectations, device count and deployment country. Ask for a sample message and an agreed acceptance test before committing to a data interface.
收到消息不一定等于测量数据新鲜
即使现场设备已经停止上报，看板仍可能显示看似合理的压力或液位。验收要求应分别定义已连接、近期收到数据和测量有效三个状态。连接指示本身不能证明显示样本的时间和质量。本文提出的是应用层设计核对建议，不代表某一 WESIVO 固件已实现全部相关行为。
分别记录测量时间与接收时间
请先索取实际遥测格式。条件具备时，将现场测量时间戳和系统接收时间分别保存，并约定时区、时钟同步以及设备重启后的处理方式。如果设备没有可靠时钟，应明确按接收时间标记样本并记录这一限制，不能将接收时间改称测量时间。
在接口处定义单位和有效性
为每个字段约定物理量、工程单位、比例因子和允许的运行范围。液位字段应说明代表传感器到液面的距离、相对参考点的高度，还是换算容积。约定缺少字段、无效值和设备诊断状态的表示方式，将不可用测量明确显示为不可用，不应悄悄用零代替。MQTT 传输不能代替项目字段映射。
将投递语义与业务记录分开
OASIS 将 MQTT QoS 1 定义为至少一次投递，因此可能出现重复消息。保留消息可以在新订阅建立时提供已存状态，但并不自动代表近期读数，这些机制也不能验证传感器精度。应用层应依据可用的设备标识、样本标识或序号约定去重方式，不宜仅用 MQTT 报文标识符作为永久历史记录键。
约定数据何时过期
根据预期上报周期、通信行为和应用需求，确定数据过期阈值，并将其记录为项目参数，不应对所有无线仪表发布统一时间值。应在读数旁显示最近有效样本的时间与数据年龄，分别定义连接丢失、迟到样本以及连接正常但测量无效时的处理方式。
验证恢复与客户数据隔离
在受控调试中测试上报中断、重新连接和迟到或重复样本，确认迟到数据不会悄悄覆盖较新的当前读数，并记录历史数据处理规则。检查每个客户账号只能访问已分配设备。设备归属和访问权限需要在平台中实现，不能仅凭主题名称推定已具备隔离能力。
用于 WESIVO 选型核对
已发布的 WESIVO 728W 信息列有 MQTT 及 LoRa、Wi-Fi 或蓝牙可选接口。接入前应确认实际订购接口、协议版本及支持行为，4G 雷达型号需另行核对平台协议。询价请提供接收平台、要求的字段映射、上报要求、设备数量和部署国家；在确定数据接口前，索取实际样例并约定验收测试。
沟通您的应用需求
请提供介质、工况、连接、输出、数量及收货地区，WESIVO 将在报价前核对配置。