Troubleshooting Best Practices for Data Acquisition Systems

您当前的故障排除方法是否与您希望它们一样有帮助？本文讨论了您可以使用的最佳实践的许多故障排除，这可能会帮助您确定问题的来源，并更快地恢复数据收集。

当我第一次开始在Campbell Scientific工作时，我们更多的经验丰富的应用工程师之一在他的办公桌附近有一个标志，问一个简单的问题：“你的数据记录器是否打开了？”我询问了这个标志，应用工程师（AE）与我分享了故事。

Several years before, the AE had received an urgent call from a customer who was having trouble communicating with her data logger. She was working in a remote area and had left the data logger to run unattended for a week. When she returned to collect the data, she couldn't establish communication between her data logger and a laptop. The AE helped her to perform all of the standard troubleshooting steps for a communications issue, but nothing helped, and the customer became increasingly frustrated. Finally, in desperation, the AE asked, “Is your data logger turned on?” There was a short pause, and then the embarrassed customer hung up the phone without further discussion.

Although the customer was embarrassed, she didn't need to be.Forgetting to check something as basic as whether there is power to the system is a common mistake- 即使我们每天与坎贝尔科学装备一起工作的人之间。AE展示了这个标志，提醒他在排除故障时始终从基础开始。

Understanding Troubleshooting

故障排除只是用于查找问题源的过程，然后使用解决问题。当您面对涉及测量，外围和通信硬件的复杂系统时;软件;电源;和传感器，可能出错的东西的纯粹数量可能似乎压倒了。但是，您可以使用少数工具和一些简单的测试消除许多可能的问题。

Tools and Tests

您可以使用简单的数字万用表执行许多故障排除测试。良好的万用表提供了数据记录器测量的电压的独立验证。该设备允许您自主检查预期电压并验证连接点之间的电连续性。

A digital multimeter is just one tool for your troubleshooting toolbox. The essential tools to troubleshoot a Campbell Scientific data acquisition system include the following:

• 数字万用表
• Small (2.5 mm) flat-bladed screwdriver
• 剥线机
• Data logger keyboard/display or computer for communicating with the data logger

Note:You may need a Phillips #1 screwdriver to remove some components from their mountings or to remove their covers.

推荐的佛r You:Read our"Tips and Tricks: What's in Your Toolbox?" article。

You can use these tools to conduct common troubleshooting tests such as the following:

• Measuring voltage
• Testing for continuity
• Swapping locations of sensor connections
• Changing the environment the sensor experiences to force a change of reading

In many cases, it’s helpful if you can think of a way to independently verify the right answer. For example, if a temperature sensor doesn't seem to be giving correct readings, you could do a simple test by putting it in ice water, which is independently known to have a temperature of 0°C.

Asking the Right Question

虽然工具和测试有助于您的故障排除工作，ultimately, successful troubleshooting always depends on asking and answering the right question。You can't find the right answer without finding the right question first. The right question is the one that uncovers a problem.

It's normal to approach a problem with a set of assumptions. To find the problem that must be solved, try asking yourself a list of questions that begin with “Is my assumption correct that . . . ?” You can use your answers in this way:

• When the answer is “no,” you have identified at least one right question, and you can take corrective action. In other words, test each assumption until one or more tests fail.
• 当答案是“是的”时，必须通过回答这种后续问题来支持：“我如何知道这一点。。。是真的？”每个“是”答案需要一个明确的答案的简单测试。

For example: 我的假设是正确的,数据记录器力量? Yes. 我如何知道数据记录器有电力？ 由于电源导通，并且我的电压表在12V和G终端之间读取13.4V。

Understanding the Measurement Process

To systematically find the right question, it's important to have a basic understanding of what is being measured and how that measurement is processed. Typically, the process looks like this:

1. 一些环境参数由传感器转换为电信号。
2. That electrical signal is measured and digitized by a data logger.
3. The measurement is processed statistically and stored in data logger memory.
4. 最终将测量转移到计算机以进行分析和显示。

很常见的是，在您仔细查看计算机上的数据之前，您可能找不到测量问题并看到没有意义的测量号。这通常是故障排除开始的程度。当您花时间了解传感器如何响应环境变化以及它发送到数据记录器的电气输出是什么时候，此过程会变得更加光滑。

Horses, Not Zebras

一个受欢迎的医学谚语说：“当你听到Hofbeats时，想想马，而不是斑马，”意味着当面对诊断问题时，最好先看看预期的原因，而不是异国情调。当您处理仪器问题时，预期原因的简短列表包括以下内容：

• Physical damage to electronic components
• 缺电器
• 系统组件之间的电气连接问题
• 软件设置或逻辑中的错误

通过一点点实践，您可以开发自己的方法，以系统地测试问题的更常见原因。

常见问题

当您对测量设备进行故障排除时，请记住这些常见问题：

• Power issues—bad battery, bad connection, ac outlet not energized, battery capacity too small
• Wiring issues—loose or damaged wires, wires connected to wrong terminals
• Programming issues—data logger program not matching the physical wiring, wrong settings in program instructions, logical statements that never evaluate as true

Remember these common problems when you troubleshoot your communications equipment:

• Power issues—communications hardware not receiving power
• 配置问题 - 固件或通信软件中的设置，帐户设置
• 系统问题 - 天线尺寸，视线上的障碍，无线电干扰，防火墙，行政权限

您可以使用简单的过程隔离每个问题并测试您的假设。每次发现假设不持有，您都至少提出了一个正确的问题，并且可以开始向解决方案移动。

Stepping Back

Sometimes it's good to take a break from testing and summarize what you have learned so far. Start with the question "What do I know for sure?" and list what you have learned from your simple tests. This is especially helpful if you have been trying a lot of different tests and you start to lose track of the results.返回看看大局通常揭示了你尚未考虑过测试的基本假设，这可能是问题来源的。

“您的数据记录器是否已打开？”是一个简单的问题，但答案可能会节省时间和挫折感。

Do you have a favorite troubleshooting story or best-practice tip? Feel free to share it.