34970A上电时NVram错误

我成功找到了913错误的所有者 - 这是测试失败时出现的34907A多功能模块。
NVRam在那里吗？
如果未安装，则开机时没有错误消息。
没有第二个已知良好的07型模块来比较它。
仍在尝试重新获得串口通信。
在确定MC145407接口集成电路的范围时，它似乎可以毫无问题地接收和传输输入数据，而PC16550则无需向外传输任何数据。



     以下为原文

  I've managed to track down the owner of the 913 error - it's the 34907A multifunction module that was present in the test failure. Is NVRam in there?

If it's not installed, then there is no error message at power-on. There isn't a second known-good 07 type module to compare this to.

Still trying to regain serial port communications. Scoping the MC145407 interface IC, it seems to receive and transmit incoming data without issues, there's just nothing coming back from the PC16550 for transmission outwards.

34907A确实包含非易失性RAM。
您可以尝试校准34907A以查看是否可以解决问题。
该程序位于34970A / 72A服务指南中，您可以在Agilent网站上找到该指南。



     以下为原文

  The 34907A does contain non volatile RAM.  You could try calibrating the 34907A to see if that fixes the problem.  The procedure is in the 34970A/72A Service Guide which you can find on the Agilent web site.

34907模块校准仅适用于DAC输出。
当编程为10.0时，我从ch4得到10.6，从ch5得到9.99。
不安全的，10.6和-0.6之间的任何输入，作为ch4的校准输入，都会产生706错误 - “校准值超出范围”。
要走了。



     以下为原文

  The 34907 module calibration applies to the DAC outputs only. I'm getting 10.6 from ch4 and 9.99 from ch5, when programmed to 10.0.  

Unsecured, any input between 10.6 and -0.6, as a calibration input for ch4, gets a 706 error - 'Calibration value out of range'. 

got to go.

34970A的重复闪烁显示和蜂鸣声由34901模块拥有，该模块在事件发生时位于插槽1中。
该模块主要是在3通道瓦特计的背板连接器上读取低压模拟信号，信号以安全接地框为参考。
检查回来，这就是它所做的一切。
无论如何，它继续引起同样的行为，因此没有明显的损坏或供应不规则，它可以坐在架子上一段时间，直到有更多的时间来弄明白。
RL



     以下为原文

  The repeated flashing display and beeping of the 34970A is owned by the 34901 module that was present in slot one at the time of the event. This module was mostly reading low voltage analog signals on a 3-channel wattmeter's  back-panel connector, with signals referenced to the safety earth frame. Checking back, that was ALL that it was doing.

Anyways, it continues to evoke this same behavior, so without visible damage or supply irregularities, it can sit on the shelf for a while until there's more time to figure it out.

RL

杀死第二个34970A单位花了大约2个小时，症状和结果相同。
新的34970A，经过预先测试，用于配置加载等，但没有内存备份，被替换为串行无端口记录器的位置。
这一直在悄悄地完成它的工作，仍然允许三个模块的手动测量和I / O.
施加微小功率后，新记录仪中的显示开始闪烁，并且发出点击继电器的声音，让人想起冰雹。
我拉了插头。
第二个记录器不再具有串行通信，不再识别预先测试的34901A模块，预先测试的34907A模块导致显示器闪烁/电源复位，USB串行端口适配器是吐司。
那是我的预算不见了。
如果我设法找出原因，我会留言。
但是，如果没有关于记录器和模块中实际损坏的更多信息，则永远不会有真正的根本原因分析。
没有任何东西是可见或明显的，保存安静的PIC和维修这些物品不是“安捷伦维修策略”。
在被测系统和记录PC之间存在某种接地故障，尽管这两者之间的短路实际上会产生泄漏电流（400uA至2mA）的增加，而不是提供外部路径。
数据记录器如何通过测量开路的隔离测量继电器触点提供此路径，这是另一个问题。
模块1的瓦特计监视端子上的最大节点电压为5VDC满量程，模块2的输出监视端子上为35VAC，没有连接到I / O模块3。



     以下为原文

  It took about 2 hours to kill the second 34970A unit, with the same symptoms and ~results.

The new 34970A, pretested for configuration loading etc, but with no memory back-up, was substituted into a the position of the serial portless logger. This had been quietly doing its job, still allowing manual measurement and I/O from three modules. 

The minute power was applied, the display in the new logger started to flash and there was a sound of clicking relays reminiscent of a hailstorm. I pulled the plug.

The second logger no longer has serial communications, a pretested 34901A module is no longer recognized, a pretested 34907A module causes display flashing/power reset, and a USB-serial port adapter is toast.

That's my budget gone. If I ever manage to figure out the cause, I'll leave a note. 

Without more info on the actual damage in the loggers and modules however, there can never be a genuine root cause analysis. Nothing is visible or evident, save quiet PICs and servicing of these items is not an 'Agilent Repair Strategy'.

It's got to have been some kind of ground fault between the system under test and that of the recording PC, though shorts placed between these two actually generate an increase in leakage current (400uA to 2mA), rather than providing an external path.

How the datalogger provides this path, through isolated measurement relay contacts that measure open circuit, is another question. The largest node voltage was 5VDC full scale on the Wattmeter monitoring terminals of module 1, 35VAC on the output monitoring terminals of module 2, with no connection to I/O module3.